JP2020085697A - Infrared detection device, infrared detection method, program to be executed by computer, and computer-readable recording medium in which program is recorded - Google Patents

Abstract

To provide an infrared detection device with which it is possible to calculate a temperature with high accuracy even in a far-infrared and a mid-infrared region.SOLUTION: An infrared detection device 10 comprises detectors 2, 3 and a calculation unit 4. The detector 2 detects the spectral irradiance I (λ, T) of an infrared ray IFR2 having a wavelength λlonger than a wavelength where blackbody spectral radiance takes a maximum value. The detector 3 detects the spectral irradiance I (λ, T) of an infrared ray IFR3 having a wavelength λlonger than the wavelength λ. The calculation unit 4 calculates the characteristic value of spectral radiance at wavelengths λ, λon the basis of approximate value of the ratio of spectral irradiances I (λ, T) and I(λ, T) and the ratio of blackbody spectral radiance at a wavelength λand blackbody spectral radiance at a wavelength λ, and calculates the temperature of an object 20 on the basis of the calculated characteristic value of spectral radiance.SELECTED DRAWING: Figure 1

Description

The present invention relates to an infrared detection device, an infrared detection method, a program to be executed by a computer, and a computer-readable recording medium recording the program.

At present, infrared detectors that detect radiant energy of infrared rays are widely used as components of radiation thermometers and gas sensors. A radiation thermometer is a device that converts infrared radiant energy that can be measured in a non-contact manner into the temperature of a target object.A gas sensor observes the attenuation rate until the infrared energy of the target object reaches the infrared detector and measures the gas concentration. It is a device that converts to.

For radiation thermometers and gas sensors, various device configurations, methods for calculating temperature and gas concentration are known. The reason for this is that the radiant energy of infrared rays is influenced by the temperature of the object, the transmittance between the object and the infrared detector, and the emissivity of the object.

In the radiation thermometer, the method of estimating the temperature from the radiant energy of infrared rays is classified by the number of wavelengths detected by the infrared detector. As a typical method, a monochromatic method that detects radiant energy of a single wavelength and converts its intensity into temperature, a two-color method that detects radiant energy of two wavelengths and converts the ratio of radiant energy into temperature It has been known. On the other hand, there is also known a multicolor method in which radiant energy of three or more wavelengths is detected to calculate temperature.

In order to calculate the temperature with high accuracy by these temperature calculating methods, the prerequisites of the respective measuring methods must be satisfied. For example, in the monochromatic method, the temperature cannot be calculated with high accuracy unless the emissivity of the object and the transmittance between the object and the infrared detector are known. On the other hand, in the two-color method, when the emissivity of the object and the transmittance between the object and the infrared detector do not depend on the wavelength, the temperature can be calculated with high accuracy.

Patent Documents 1 and 2 and the like describe methods for calculating temperature with high accuracy even when the emissivity of an object and the transmittance between the object and an infrared detector depend on the wavelength. The multicolor method of Patent Document 1 is a method of calculating a temperature by correcting the emissivity having wavelength dependence by calculating the emissivity ratio for a high-temperature object. On the other hand, there is also a method of correcting the transmittance having wavelength dependency by using another detector. For example, Patent Document 2 is a radiation thermometer in which a water vapor transmission effect is corrected by a hygrometer.

JP, 7-146179, A JP, 2014-182122, A JP-A-7-113746 JP, 2009-8527, A

However, when the emissivity of the target object and the transmittance between the target object and the infrared detector have wavelength dependency, certain limited measurement conditions are required to calculate the temperature with high accuracy. The method of Patent Document 1 can be used only when the spectral radiance emitted by the object can be approximated by Wien's law, that is, when the detection wavelength of the infrared detector is a short wavelength. For example, when the temperature of the object is 780° C., the temperature can be calculated by correcting the wavelength-dependent emissivity using an infrared detector that detects a wavelength of 1.4 to 1.8 μm. .. That is, the method of Patent Document 1 cannot be used for an object at room temperature (0 to 100° C.) or an infrared detector in the far infrared region. On the other hand, according to the method of Patent Document 2, the temperature can be calculated with high accuracy by correcting the water vapor permeability. However, a hygrometer is required as an additional measuring device, which complicates the device.

Therefore, according to the embodiment of the present invention, there is provided an infrared detection device capable of calculating temperature with high accuracy even in the far infrared region and the mid infrared region.

Further, according to the embodiment of the present invention, there is provided an infrared detecting method capable of calculating temperature with high accuracy even in the far infrared region and the mid infrared region.

Further, according to the embodiment of the present invention, there is provided a program for causing a computer to execute highly accurate temperature calculation even in the far infrared region and the mid infrared region.

Further, according to the embodiment of the present invention, there is provided a computer-readable recording medium in which a program for causing a computer to execute highly accurate temperature calculation in the far infrared region and the mid infrared region is recorded.

(Structure 1)
According to the embodiment of the present invention, the infrared detection device includes first and second detectors and a calculation unit. The first detector detects a first spectral irradiance of a first infrared ray having a first wavelength longer than a wavelength at which the black body spectral radiance has a maximum value. The second detector detects a second spectral irradiance of a second infrared ray having a second wavelength longer than the first wavelength. The calculating unit calculates a first spectral irradiance ratio, which is a ratio of the first spectral irradiance and the second spectral irradiance, a black body spectral radiance at the first wavelength, and a black body spectral at the second wavelength. The characteristic value of the spectral radiance at the first and second wavelengths is calculated based on the approximate value of the ratio with the radiance, and the temperature of the object is calculated based on the calculated characteristic value of the spectral radiance. ..

(Structure 2)
In the configuration 1, the first wavelength and the second wavelength are longer than the wavelength at which the black body spectral radiance has the maximum value.

(Structure 3)
In the configuration 1 or the configuration 2, the calculation unit is a transmittance of the first infrared ray between the object and the first and second detectors, based on the first spectral irradiance ratio and the approximate value. The first transmittance ratio, which is the ratio of the first transmittance and the second transmittance that is the second infrared transmittance between the object and the first and second detectors, is calculated as the characteristic value. Then, a square root of the first transmittance ratio is calculated by using a root including an extinction coefficient ratio which is a ratio of the first extinction coefficient of the first infrared ray and the second extinction coefficient of the second infrared ray. A calculated temperature of 1 is calculated, and the calculated first calculated temperature is calculated as the temperature of the object.

(Structure 4)
In the configuration 3, the calculation unit calculates the first calculated temperature calculated by the following formula (1) as the temperature of the object.

［式（１）において、ｈは、プランク定数であり、ｋは、ボルツマン定数であり、ｃは、光速であり、λ_２は、第１の波長であり、λ_３は、第２の波長であり、αは、対象物が放射する分光放射輝度のうち、第１および第２の検出器が検出する割合であり、Ｔ_ｅｓｔ１は、第１の算出温度であり、ε_ａ（λ_２）は、第１の吸光係数であり、ε_ａ（λ_３）は、第２の吸光係数であり、Ｉ（λ_２，Ｔ）は、第１の分光放射照度であり、Ｉ（λ_３，Ｔ）は、第２の分光放射照度であり、Ｒ_ｅｓｔは、近似値であり、Ｔは、絶対温度である。］
（構成５）
構成３または構成４において、算出部は、第１の算出温度を補正した第２の算出温度を対象物の温度として算出する。

[In the formula (1), h is Planck's constant, k is Boltzmann's constant, c is the speed of light, λ ₂ is the first wavelength, and λ ₃ is the second wavelength. _Yes , α is the ratio of the spectral radiance emitted by the object detected by the first and second detectors, T _est1 is the first calculated temperature, and ε _a (λ ₂ ) is , The first extinction coefficient, ε _a (λ ₃ ) is the second extinction coefficient, I(λ ₂ , T) is the first spectral irradiance, I(λ ₃ , T) Is the second spectral irradiance, R _est is an approximation and T is the absolute temperature. ]
(Structure 5)
In the configuration 3 or the configuration 4, the calculation unit calculates the second calculated temperature obtained by correcting the first calculated temperature as the temperature of the object.

(Structure 6)
In the configuration 5, the calculation unit calculates the second calculated temperature corrected by the following equation (2) as the temperature of the object.

［式（２）において、ｈは、プランク定数であり、ｋは、ボルツマン定数であり、ｃは、光速であり、λ_２は、第１の波長であり、λ_３は、第２の波長であり、Ｔ_ｅｓｔ１は、第１の算出温度であり、Ｔ_ｅｓｔ２は、第２の算出温度であり、ε_ａ（λ_２）は、第１の吸光係数であり、ε_ａ（λ_３）は、第２の吸光係数であり、Ｒ_ｅｓｔは、近似値であり、Ｒ（Ｔ_ｅｓｔ１）は、第１の算出温度および第１の波長における黒体分光放射輝度と、第１の算出温度および第２の波長における黒体分光放射輝度との比である。］
（構成７）
構成３において、赤外線検出装置は、第３の検出器を更に備える。第３の検出器は、第１の波長よりも短い第３の波長を有する第３の赤外線の第３の分光放射照度を検出する。算出部は、第１の透過率比から第１および第２の透過率のいずれか一方の透過率である第３の透過率を算出し、対象物から第１、第２および第３の検出器までの間における第３の赤外線の透過率である第４の透過率を第３の透過率から算出し、その算出した第４の透過率と第３の透過率とに基づいて対象物の温度を算出する。

[In Formula (2), h is Planck's constant, k is Boltzmann's constant, c is the speed of light, λ ₂ is the first wavelength, and λ ₃ is the second wavelength. _Yes , T _est1 is the first calculated temperature, T _est2 is the second calculated temperature, ε _a (λ ₂ ) is the first extinction coefficient, and ε _a (λ ₃ ) is The second extinction coefficient, R _est is an approximate value, and R(T _est1 ) is the blackbody spectral radiance at the first calculated temperature and the first wavelength, the first calculated temperature, and the second calculated temperature. Is the ratio with the blackbody spectral radiance at the wavelength of. ]
(Structure 7)
In Configuration 3, the infrared detection device further includes a third detector. The third detector detects a third spectral irradiance of a third infrared ray having a third wavelength shorter than the first wavelength. The calculator calculates a third transmittance, which is one of the first and second transmittances, from the first transmittance ratio, and performs the first, second, and third detection from the object. The fourth transmittance, which is the transmittance of the third infrared ray up to the container, is calculated from the third transmittance, and based on the calculated fourth transmittance and the third transmittance, the object Calculate the temperature.

(Structure 8)
In any one of the configurations 1 to 7, the calculation unit further calculates the absolute amount or concentration of the absorber existing between the object and the first and second detectors based on the characteristic value.

(Configuration 9)
In the configuration 8, the calculating unit further calculates the concentration of the water vapor that is the absorber based on the characteristic value, and calculates the substantial temperature from the concentration of the water vapor and the temperature of the object. Then, the first wavelength is set in the range of 3.5 to 6.0 μm, and the second wavelength is set in the range of 4.5 to 6.0 μm, or the first wavelength is It is set in the range of 8.0 to 16.0 μm, and the second wavelength is set in the range of 13.0 to 16.0 μm.

(Configuration 10)
In Configuration 8, the calculation unit further calculates the concentration of carbon dioxide that is the absorber based on the characteristic value, and calculates the comfort index from the concentration of carbon dioxide and the temperature of the object. The first wavelength is set in the range of 3.5 to 4.0 μm, and the second wavelength is set in the range of 4.0 to 4.5 μm, or the first wavelength is The wavelength is set in the range of 4.5 to 16.0 μm, and the second wavelength is set in the range of 13.5 to 16.0 μm.

(Configuration 11)
In the configuration 1, the calculating unit is an emissivity that is a ratio of the first emissivity at the first wavelength and the second emissivity at the second wavelength, based on the first spectral irradiance ratio and the approximate value. The ratio is calculated as a characteristic value, and the temperature of the object is calculated based on the calculated emissivity ratio.

(Configuration 12)
In the configuration 11, the calculating unit calculates a third emissivity which is one of the first and second emissivity based on the emissivity ratio, and based on the calculated third emissivity. To calculate the temperature of the object.

(Configuration 13)
In any one of the configurations 1 to 12, the infrared detection device further includes a wavelength selection unit. The wavelength selection unit selects the first and second wavelengths in the wavelength range from mid infrared to far infrared. The wavelength selection unit holds an accuracy rating that defines the accuracy of the calculated temperature calculated by the calculation unit, and the error between the temperature of the object in the measurement range of the temperature of the object and the calculated temperature of the object is The first and second wavelengths are selected to be less than the accuracy rating.

(Configuration 14)
In the configuration 7, two or three detectors of the first to third detectors are the same quantum well type or quantum dot type detectors. The infrared detection device further includes a control unit that controls the voltage applied to the same detector to control the wavelength to be detected.

(Configuration 15)
In the configuration 1, the first and second detectors arranged in an array form a detector group. The calculation unit performs a process of calculating a characteristic value based on the first spectral irradiance ratio and the approximate value for a plurality of sets of first and second spectral irradiances detected by a plurality of detector groups, and performs a plurality of processes. Characteristic values are calculated, a plurality of temperatures in a plurality of regions of the object are calculated based on the calculated plurality of characteristic values, and a temperature distribution of the object is calculated based on the calculated plurality of temperatures.

(Configuration 16)
In the configuration 7, the first to third detectors arranged in an array form a detector group. The calculation unit executes a process of calculating a third transmittance from the first transmittance ratio for a plurality of sets of first and second spectral irradiances detected by a plurality of detector groups, and then performs a plurality of third transmittances. Of a plurality of third transmittances, a plurality of fourth transmittances are calculated from the plurality of third transmittances, and a plurality of regions of the object based on the plurality of third transmittances and the plurality of fourth transmittances. A plurality of temperatures in is calculated, and the temperature distribution of the object is calculated based on the calculated plurality of temperatures.

(Configuration 17)
Further, according to the embodiment of the present invention, the infrared detection method includes a first spectral irradiance of a first infrared ray having a first wavelength longer than a wavelength at which the black body spectral radiance has a maximum value, A first step of detecting a second spectral irradiance of a second infrared ray having a second wavelength longer than the first wavelength, and a ratio of the first spectral irradiance and the second spectral irradiance The first and second wavelengths based on the first spectral irradiance ratio which is the ratio of the black body spectral radiance at the first wavelength to the black body spectral radiance at the second wavelength. And a third step of calculating the temperature of the object based on the calculated characteristic value of the spectral radiance.

(Structure 18)
In the configuration 17, the first and second wavelengths are longer than the peak wavelength at which the maximum value of the black body spectral radiance is obtained.

(Structure 19)
In the second step of the configuration 17 or the configuration 18, it is the transmittance of the first infrared ray between the object and the first and second detectors based on the first spectral irradiance ratio and the approximate value. The characteristic value is the first transmittance ratio, which is the ratio of the first transmittance and the second transmittance which is the transmittance of the second infrared rays between the object and the first and second detectors. calculate. In addition, in the third step, the first transmittance ratio using a root including an extinction coefficient ratio which is a ratio of the first extinction coefficient of the first infrared ray and the second extinction coefficient of the second infrared ray. The square root is calculated to calculate the first calculated temperature, and the calculated first calculated temperature is calculated as the temperature of the object.

(Configuration 20)
In the third step of the configuration 19, the first calculated temperature calculated by the following equation (1) is calculated as the temperature of the object.

［式（１）において、ｈは、プランク定数であり、ｋは、ボルツマン定数であり、ｃは、光速であり、λ_２は、第１の波長であり、λ_３は、第２の波長であり、αは、対象物が放射する分光放射輝度のうち、第１および第２の検出器が検出する割合であり、Ｔ_ｅｓｔ１は、第１の算出温度であり、ε_ａ（λ_２）は、第１の吸光係数であり、ε_ａ（λ_３）は、第２の吸光係数であり、Ｉ（λ_２，Ｔ）は、第１の分光放射照度であり、Ｉ（λ_３，Ｔ）は、第２の分光放射照度であり、Ｒ_ｅｓｔは、近似値であり、Ｔは、絶対温度である。］
（構成２１）
構成１９または構成２０の第３のステップにおいて、第１の算出温度を補正した第２の算出温度を対象物の温度として算出する。

[In the formula (1), h is Planck's constant, k is Boltzmann's constant, c is the speed of light, λ ₂ is the first wavelength, and λ ₃ is the second wavelength. _Yes , α is the ratio of the spectral radiance emitted by the object detected by the first and second detectors, T _est1 is the first calculated temperature, and ε _a (λ ₂ ) is , The first extinction coefficient, ε _a (λ ₃ ) is the second extinction coefficient, I(λ ₂ , T) is the first spectral irradiance, I(λ ₃ , T) Is the second spectral irradiance, R _est is an approximation and T is the absolute temperature. ]
(Configuration 21)
In the third step of the configuration 19 or the configuration 20, the second calculated temperature obtained by correcting the first calculated temperature is calculated as the temperature of the object.

(Configuration 22)
In the third step of the configuration 21, the second calculated temperature corrected by the following equation (2) is calculated as the temperature of the object.

［式（２）において、ｈは、プランク定数であり、ｋは、ボルツマン定数であり、ｃは、光速であり、λ_２は、第１の波長であり、λ_３は、第２の波長であり、Ｔ_ｅｓｔ１は、第１の算出温度であり、Ｔ_ｅｓｔ２は、第２の算出温度であり、ε_ａ（λ_２）は、第１の吸光係数であり、ε_ａ（λ_３）は、第２の吸光係数であり、Ｒ_ｅｓｔは、近似値であり、Ｒ（Ｔ_ｅｓｔ１）は、第１の算出温度および第１の波長における黒体分光放射輝度と、第１の算出温度および第２の波長における黒体分光放射輝度との比である。］
（構成２３）
構成１９第１のステップにおいて、第１の波長よりも短い第３の波長を有する第３の赤外線の第３の分光放射照度を更に検出する。そして、第２のステップにおいて、第１の透過率比から第１および第２の透過率のいずれか一方の透過率である第３の透過率を算出するとともに、対象物から第１、第２および第３の検出器までの間における第３の赤外線の透過率である第４の透過率を第３の透過率から算出し、第３のステップにおいて、算出された第４の透過率と第３の透過率とに基づいて対象物の温度を算出する。

[In Formula (2), h is Planck's constant, k is Boltzmann's constant, c is the speed of light, λ ₂ is the first wavelength, and λ ₃ is the second wavelength. _Yes , T _est1 is the first calculated temperature, T _est2 is the second calculated temperature, ε _a (λ ₂ ) is the first extinction coefficient, and ε _a (λ ₃ ) is The second extinction coefficient, R _est is an approximate value, and R(T _est1 ) is the blackbody spectral radiance at the first calculated temperature and the first wavelength, the first calculated temperature, and the second calculated temperature. Is the ratio with the blackbody spectral radiance at the wavelength of. ]
(Structure 23)
Configuration 19 In a first step, a third spectral irradiance of a third infrared light having a third wavelength shorter than the first wavelength is further detected. Then, in the second step, the third transmittance, which is one of the first and second transmittances, is calculated from the first transmittance ratio, and the first and second transmittances are calculated from the object. And the fourth transmittance, which is the transmittance of the third infrared ray between the third detector and the third detector, is calculated from the third transmittance, and in the third step, the calculated fourth transmittance and the fourth transmittance are calculated. The temperature of the object is calculated based on the transmittance of No. 3 and the transmittance of No. 3.

(Configuration 24)
In any one of Configuration 17 to Configuration 23, the infrared detection method is configured to calculate an absolute amount or concentration of an absorber existing between the object and the first and second detectors based on the characteristic value. The method further comprises steps.

(Structure 25)
In a second step of the configuration 17, the radiation that is the ratio of the first emissivity at the first wavelength and the second emissivity at the second wavelength based on the first spectral irradiance ratio and the approximation. The rate ratio is calculated as the characteristic value, and in the third step, the temperature of the object is calculated based on the calculated emissivity ratio.

(Configuration 26)
In the second step of the configuration 25, the third emissivity, which is one of the first and the second emissivity, is calculated based on the emissivity ratio, and the third emissivity is calculated in the third step. The temperature of the object is calculated based on the third emissivity.

(Structure 27)
In any one of the configurations 17 to 26, the infrared detection method further includes a sixth step of selecting the first and second wavelengths in the wavelength range from the mid infrared to the far infrared. Then, in the sixth step, the error between the temperature of the object in the measurement range of the temperature of the object and the calculated temperature of the object is set to be smaller than the accuracy rating that defines the accuracy of the calculated temperature to be calculated. Select the first and second wavelengths.

(Structure 28)
In any one of Configuration 17 to Configuration 27, the first detector for detecting the first spectral irradiance and the second detector for detecting the second spectral irradiance are the same quantum well type or quantum dot type. It consists of a detector. The infrared detection method further includes a seventh step of applying a voltage to the same detector to control the wavelengths detected by the first and second detectors to the first and second wavelengths, respectively.

(Configuration 29)
In any one of Configuration 23 to Configuration 27, a first detector that detects the first spectral irradiance, a second detector that detects the second spectral irradiance, and a third detector that detects the third spectral irradiance. The detectors of No. 3 are the same detectors of quantum well type or quantum dot type. The infrared detection method further includes an eighth step of applying a voltage to the same detector to control the wavelengths detected by the first to third detectors to the first to third wavelengths, respectively.

(Configuration 30)
In the configuration 17, the first detector that detects the first spectral irradiance and the second detector that detects the second spectral irradiance form a detector group arranged in an array. In the first step, each of the plurality of detector groups detects the first and second spectral irradiances, and in the second step, the characteristic value is determined based on the first spectral irradiance ratio and the approximate value. The calculation process is performed on a plurality of sets of first and second spectral irradiances to calculate a plurality of characteristic values, and in a third step, a plurality of characteristic values in a plurality of regions of the object are calculated based on the plurality of characteristic values. The temperature is calculated, and the temperature distribution of the object is calculated based on the calculated plurality of temperatures.

(Configuration 31)
In the configuration 23, the first detector that detects the first spectral irradiance, the second detector that detects the second spectral irradiance, and the third detector that detects the third spectral irradiance are: A group of detectors arranged in an array is constructed. In the first step, each of the plurality of detector groups detects the first to third spectral irradiances, and in the second step, a process of calculating the third transmittance from the first transmittance ratio. For a plurality of sets of first and second spectral irradiances detected by a plurality of detector groups to calculate a plurality of third transmittances, and to calculate a plurality of fourth transmittances from the plurality of third transmittances. The transmittance is calculated, and in the third step, a plurality of temperatures in a plurality of regions of the object are calculated based on the plurality of third transmittances and the plurality of fourth transmittances, and the calculated plurality of temperatures are calculated. The temperature distribution of the object is calculated based on

(Configuration 32)
Further, according to the embodiment of the present invention, the program is such that the receiving means sets the first spectral irradiance of the first infrared ray having the first wavelength and the second wavelength longer than the first wavelength. A first step of receiving the second spectral irradiance of the second infrared ray having, and a first spectral irradiance ratio which is a ratio of the first spectral irradiance and the second spectral irradiance by the calculating means. And a characteristic value of the spectral radiance at the first and second wavelengths based on an approximate value of the ratio of the black body spectral radiance at the first wavelength and the black body spectral radiance at the second wavelength. This is a program for causing the computer to execute the second step of performing and the third step of calculating the temperature of the object based on the calculated characteristic value of the spectral radiance.

(Configuration 33)
In the configuration 32, the first and second wavelengths are longer than the peak wavelength at which the maximum value of the black body spectral radiance is obtained.

(Structure 34)
Further, according to the embodiment of the present invention, the recording medium is a computer-readable recording medium in which the program according to claim 32 or 33 is recorded.

It is possible to calculate the temperature with high accuracy in the far infrared region and the mid infrared region.

1 is a schematic diagram of an infrared detection device according to a first embodiment of the present invention. It is a figure which shows the relationship between spectral radiance and wavelength. 4 is a flowchart for explaining the detection method according to the first embodiment for detecting the temperature of an object and/or the absolute amount or concentration of an absorber. It is a flowchart which shows the selection method which selects _two wavelength (lambda) ₂ ,(lambda) ₃ based on the accuracy rating of a radiation thermometer and the measuring range of the temperature of a target object. It is a flowchart which shows another selection method which selects _two wavelength (lambda) ₂ ,(lambda) ₃ based on the accuracy rating of a radiation thermometer, and the measuring range of the temperature of a target object. 6 is a flowchart showing a detection method for detecting the temperature of an object in the first embodiment. It is a figure which shows the relationship between a transmittance and a wavelength. It is a figure which shows the temperature difference of the temperature of the set target object and the calculated temperature obtained by simulation. It is a figure which shows the temperature difference between the temperature of the set target object and the correction|amendment calculated temperature obtained by simulation. It is a figure which shows the relationship between the transmittance|permeability of water vapor and wavelength. It is a figure which shows the transmittance|permeability of the carbon dioxide in a certain humidity, and the relationship of a wavelength. FIG. 6 is a schematic diagram of an infrared detection device according to a second embodiment. 9 is a flowchart for explaining a detection method according to the second embodiment for detecting the temperature of an object and/or the absolute amount or concentration of an absorber. It is a figure which shows the temperature difference of the temperature of the set target object and the calculated temperature obtained by simulation. FIG. 9 is a schematic diagram of an infrared detection device according to a third embodiment. 9 is a flowchart showing a detection method for detecting the temperature of an object in the third embodiment. FIG. 3 is a schematic diagram of an infrared detection device for detecting the temperature distribution of an object according to the embodiment of the present invention. 18 is a flowchart for explaining the operation of the infrared detection device shown in FIG. 17.

Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference characters and description thereof will not be repeated.

[Embodiment 1]
1 is a schematic diagram of an infrared detection device according to a first embodiment of the present invention. Referring to FIG. 1, infrared detection device 10 according to the first embodiment includes detectors 2 and 3 and calculation unit 4.

The detectors 2 and 3 detect infrared rays belonging to the wavelength range of 3 to 16 μm from mid infrared to far infrared. More specifically, the detector 2 detects the spectral irradiance I(λ ₂ , T) of the infrared ray IFR ₂ having the wavelength λ ₂ belonging to the wavelength range of 3 to 16 μm among the infrared rays emitted from the object 20. Then, the detected spectral irradiance I(λ ₂ , T) is output to the calculation unit 4. The detector 3 detects the spectral irradiance I(λ ₃ , T) of the infrared IFR ₃ having the wavelength λ ₃ (>λ ₂ ) belonging to the wavelength range of ₃ to 16 μm among the infrared rays radiated from the object 20. , And outputs the detected spectral irradiance I(λ ₃ , T) to the calculation unit 4.

The wavelengths λ ₂ and λ ₃ may include a certain wavelength range. In this case, the wavelengths λ ₂ and λ ₃ mean that the center wavelengths are the wavelengths λ ₂ and λ ₃ . The narrower the wavelength range, the higher the temperature detection accuracy.

In the first embodiment, if the wavelengths λ ₂ and λ ₃ are longer than the peak wavelength at which the maximum value of the black body spectral radiance is obtained, the temperature can be calculated with higher accuracy for the reason described later. Further, the emissivity ε(λ ₂ ), ε(λ ₃ ) and the extinction coefficients ε _a (λ ₂ ), ε _a (λ ₃ ) are assumed to be known.

The calculation unit 4 includes a transmittance calculation table 42, a brightness ratio parameter 43, and a wavelength selection unit 44. The transmittance calculation table 42 includes the relationship between the transmittance ratio and the transmittance. The luminance ratio parameter 43 is composed of an approximate value R _est of the ratio of the black body spectral radiance. The wavelength selection unit 44 selects the wavelengths λ ₂ and λ ₃ based on the accuracy rating of the radiation thermometer and the measurement range of the temperature of the object 20 by the method described later.

The calculation unit 4 receives the spectral irradiance I(λ ₂ , T) from the detector 2 and the spectral irradiance I(λ ₃ , T) from the detector 3. Then, the calculation unit 4 uses the transmittance calculation table 42 and the brightness ratio parameter 43 to obtain the spectral irradiances I(λ ₂ , T), I(λ ₃ , T) and the approximate value R _est by a method described later. Based on this, the temperature T of the target object 20 and/or the absolute amount or concentration of the absorber ABS existing between the target object 20 and the detectors 2 and 3 is calculated.

Each of the detectors 2.3 is a detector that performs photoelectric conversion with an InGaAs bandgap, a detector that has a wavelength filter mounted on a thermal detector such as a bolometer, and energy levels of multilayered quantum dots. And a quantum dot detector that performs photoelectric conversion by utilizing the above, and a quantum well detector that performs photoelectric conversion by utilizing the energy levels of quantum wells laminated in multiple layers.

The detectors 2 and 3 may be the same or different from each other. If the detectors 2, 3 are the same, that is, the two detectors 2, 3 are constituted by one detector, the detectors 2, 3 may be quantum dot detectors or quantum well detectors. Become. The quantum dot detector or the quantum well detector can control the detection wavelength according to the applied voltage. As a result, only one detector is required, so that the infrared detection device 10 can be downsized and reduced in cost. When the two detectors 2 and 3 are constituted by one detector, the infrared detection device 10 detects the voltage V ₂ for setting the wavelength to be detected to the wavelength λ ₂ (a quantum dot type detector or a quantum dot type detector). Control unit for applying the voltage V ₃ for setting the wavelength to be detected to the wavelength λ ₃ to the detector (comprising a quantum dot detector or a quantum well detector) Is further provided.

[Calculation method of target temperature]
The spectral irradiance I(λ ₂ , T) detected by the detector 2 is represented by the following equation.

式（１）において、αは、検出割合であり、τ（λ_２）は、透過率であり、ε（λ_２）は、放射率である。Ｂ（λ_２，Ｔ）は、波長λ_２および温度Ｔにおける黒体分光放射輝度である。

In Equation (1), α is the detection ratio, τ(λ ₂ ) is the transmittance, and ε(λ ₂ ) is the emissivity. B(λ ₂ , T) is the blackbody spectral radiance at wavelength λ ₂ and temperature T.

The detection ratio α is the ratio of the spectral radiance detected by the detector 2 or the detector 3 to the spectral radiance emitted by the object 20. Then, the detection ratio α is determined by the shape of the object 20, the distance between the object 20 and the detectors 2, 3, and the orientation of the detectors 2, 3. In the embodiment of the present invention, the detectors 2 and 3 may be calibrated to determine the detection ratio α, or a design value determined by the focal length of the lens or the like may be used as the detection ratio α.

The transmittance τ(λ ₂ ) is the transmittance of the infrared IFR2 between the object 20 and the detectors 2 and 3, and the spectral radiance emitted by the object 20 propagates to the detectors 2 and 3 through the optical path. It is the ratio of

The emissivity ε(λ ₂ ) is the ratio of the spectral radiance emitted by the object 20 to the black body spectral radiance in thermal radiation at the wavelength λ ₂ .

The blackbody spectral radiance B(λ ₂ , T) shown in the equation (1) is represented by the following equation (Planck's equation).

式（２）において、ｈは、プランク定数であり、ｃは、光速であり、ｋは、ボルツマン定数であり、Ｔは、絶対温度である。

In equation (2), h is Planck's constant, c is the speed of light, k is the Boltzmann's constant, and T is the absolute temperature.

The equations (1) and (2) described above also hold for the spectral irradiance I(λ ₃ , T) detected by the detector 3.

Therefore, the following equation is obtained from the equation (1) for the spectral irradiance I(λ ₂ , T) and the equation (1) for the spectral irradiance I(λ ₃ , T).

このように、透過率の比τ（λ_２）／τ（λ_３）は、分光放射照度の比Ｉ（λ_２，Ｔ）／Ｉ（λ_３，Ｔ）、放射率の比ε（λ_３）／ε（λ_２）および黒体分光放射輝度の比Ｂ（λ_３，Ｔ）／Ｂ（λ_２，Ｔ）によって表される。

Thus, the transmittance ratio τ(λ ₂ )/τ(λ ₃ ) is the spectral irradiance ratio I(λ ₂ ,T)/I(λ ₃ ,T) and the emissivity ratio ε(λ _{3 ).} )/Ε(λ ₂ ) and the black body spectral radiance ratio B(λ ₃ , T)/B(λ ₂ , T).

In the first embodiment, the method of calculating the transmittance is used when there is a correspondence between the transmittance ratio and the transmittance. As an example of this, a law relating to the attenuation of infrared rays in the presence of an absorber, such as Lambert-Beer's law, can be applied.

Lambert-Beer's law is expressed by the following equation.

式（４）において、ε_ａ（λ_２）は、波長λ_２を有する赤外線ＩＦＲ２の吸光係数である。ｃ_ａは、対象物２０から検出器２，３までの間に存在する吸収体ＡＢＳの濃度である。ｌは、対象物２０から検出器２，３までの距離である。

In Expression (4), ε _a (λ ₂ ) is the extinction coefficient of the infrared IFR2 having the wavelength λ ₂ . c _a is the concentration of the absorber ABS existing between the object 20 and the detectors 2 and 3. l is the distance from the object 20 to the detectors 2 and 3.

Since the formula (4) holds for the transmittance τ(λ ₃ ), the formula (4) for the transmittance τ(λ ₂ ) and the formula (4) for the transmittance τ(λ ₃ ) Clearing the concentration c _a and the distance l, the following equation is obtained.

式（５）は、透過率の比τ（λ_３）／τ（λ_２）から透過率τ（λ_２）を算出できることを意味する。なお、実施の形態１においては、吸光係数ε_ａ（λ_１），ε_ａ（λ_２）は、既知であるものとする。

Equation (5) means that the transmittance τ(λ ₂ ) can be calculated from the transmittance ratio τ(λ ₃ )/τ(λ ₂ ). In the first embodiment, the extinction coefficients ε _a (λ ₁ ) and ε _a (λ ₂ ) are known.

The transmittance calculation table 42 includes a relationship between the transmittance ratio τ(λ ₃ )/τ(λ ₂ ) and the transmittance τ(λ ₂ ). That is, the transmittance calculation table 42 calculates beforehand the relationship between the transmittance ratio τ(λ ₃ )/τ(λ ₂ ) and the transmittance τ(λ ₂ ) by experiments in the usage environment of the detectors 2 and _3. Then, the relationship between the calculated transmittance ratio τ(λ ₃ )/τ(λ ₂ ) and the transmittance τ(λ ₂ ) is included.

FIG. 2 is a diagram showing the relationship between spectral radiance and wavelength. In FIG. 2, the vertical axis represents the spectral radiance and the horizontal axis represents the wavelength.

Referring to FIG. 2, the wavelength dependence of the spectral radiance is represented by Expression (2) (Planck's expression). The relationship between the peak wavelength λ _max that gives the maximum value of the spectral radiance and the temperature T is generally known as the Wien's displacement law expressed by the following equation.

式（６）において、ｂは、２９００[Ｋ・μｍ]である。

In the formula (6), b is 2900 [K·μm].

The conditions for calculating the transmittance and the temperature of the object 20 using the _two detection wavelengths λ ₂ and λ ₃ will be described.

Condition 1) the extinction coefficient of the absorption coefficient of the detection wavelength λ ₂ ε _a (λ ₂₎ is the detection wavelength λ ₃ ε _a (λ ₃₎ differ.

When the extinction coefficient ε _a (λ ₂ ) is the same as the extinction coefficient ε _a (λ ₃ ), for example, the transmittance τ(λ ₂ ) cannot be calculated by the formula (5), so Condition 1 is required. Is.

Condition 2) The two detection wavelengths λ ₂ and λ ₃ are long wavelengths. For example, the two detection wavelengths λ ₂ and λ ₃ are long wavelengths with respect to the wavelength λ _{max at} which the spectral radiance of the object 20 has a peak value.

Condition 3) The wavelength difference between the _two detection wavelengths λ ₂ and λ ₃ is less than or equal to the threshold value Δλ _th . The threshold value Δλ _th is, for example, 2 μm.

Then, in the first embodiment, the following three combinations can be used as the combination of the conditions 1 to 3.

(I) Combination of conditions 1 to 3 (II) Combination of conditions 1 and 2 (III) Combination of conditions 1 and 3 When the wavelengths λ ₂ and λ ₃ satisfy the above condition 2, black body spectroscopy The ratio of the radiance B(λ ₂ , T) and the black body spectral radiance B(λ ₃ , T) is represented by the following equation, and the temperature dependence is reduced.

検出波長λ_２および検出波長λ_３が長波長であるほど、黒体分光放射輝度は、レイリー・ジーンズの法則に近づき、黒体分光放射輝度の比の温度依存性は、小さくなる。

As the detection wavelength λ ₂ and the detection wavelength λ ₃ are longer, the blackbody spectral radiance approaches the Rayleigh-Jean's law, and the temperature dependence of the ratio of the blackbody spectral radiance decreases.

In particular, when the detection wavelength λ ₂ and the detection wavelength λ ₃ are long wavelengths with respect to the wavelength at which the spectral radiance of the object 20 has a peak value, the blackbody spectral radiance is black according to Rayleigh-Jean's law. The body spectral radiance ratio becomes independent of temperature. In this case, the black body spectral radiance ratio is expressed by the following equation.

２つの検出波長λ_２，λ_３の波長差がしきい値Δλ_ｔｈ以下である場合、黒体分光放射輝度Ｂ（λ_２，Ｔ）と黒体分光放射輝度Ｂ（λ_３，Ｔ）は、概ね等しくなる。即ち、次式が成立する。

When the wavelength difference between the _two detection wavelengths λ ₂ and λ ₃ is less than or equal to the threshold value Δλ _th , the black body spectral radiance B(λ ₂ , T) and the black body spectral radiance B(λ ₃ , T) are It is almost equal. That is, the following equation is established.

発明者は、２つの波長λ_２，λ_３が上記の条件２または条件３を満たすとき、黒体分光放射輝度の比Ｂ（λ_３，Ｔ）／Ｂ（λ_２，Ｔ）の温度依存性が小さくなることを見出した。そこで、実施の形態１においては、黒体分光放射輝度の比の温度依存性が小さくなることを用いて対象物２０の温度を算出する。

The inventor has found that when the two wavelengths λ ₂ and λ ₃ satisfy the above condition 2 or condition 3, the temperature dependence of the black body spectral radiance ratio B(λ ₃ ,T)/B(λ ₂ ,T). It was found that Therefore, in the first embodiment, the temperature of the target object 20 is calculated by using the fact that the temperature dependence of the ratio of the blackbody spectral radiance is reduced.

In this case, the combinations shown in (I) to (III) above are used. Then, when the combination of the above (I) is used, the temperature of the object 20 can be calculated most accurately.

As for the spectral irradiance I(λ ₃ , T), the above-mentioned formula (1) is established. Therefore, the formula (1) for the spectral irradiance I(λ ₂ , T) and the spectral irradiance I(λ ₃ , T) are used. The following equation is obtained from the equation (1) for () and the equation (9).

式（１０）は、分光放射照度の比Ｉ（λ_２，Ｔ）／Ｉ（λ_３，Ｔ）、放射率の比ε（λ_３）／ε（λ_２）および黒体分光放射輝度の比Ｒによって透過率の比τ（λ_２，Ｔ）／τ（λ_３，Ｔ）を算出できることを意味する。

Formula (10) is the ratio of spectral irradiance I(λ ₂ , T)/I(λ ₃ , T), the ratio of emissivity ε(λ ₃ )/ε(λ ₂ ) and the ratio of blackbody spectral radiance. It means that the ratio of transmittance τ(λ ₂ , T)/τ(λ ₃ , T) can be calculated by R.

In the first embodiment, the black body spectral radiance ratio R is set to the approximate value R _est of the black body spectral radiance ratio as the brightness ratio parameter 43. That is, the brightness ratio parameter 43 is composed of the approximate value R _est .

The calculating unit 4 calculates the transmittance ratio τ(λ ₂ )/τ(λ ₃ ) by the equation (10). Then, the calculation unit 4 substitutes the calculated transmittance ratio τ(λ ₂ )/τ(λ ₃ ) into the equation (5) to calculate the transmittance τ(λ ₂ ).

After that, the calculation unit 4 calculates the detection ratio α, the calculated transmittance τ(λ ₂ ), the spectral irradiance I(λ ₂ , T) detected by the detector 2 and the known emissivity ε(λ ₂ ). The black body spectral radiance B(λ ₂ , T) is calculated by substituting it into the equation (1), and the calculated black body spectral radiance B(λ ₂ , T) is substituted into the equation (2). Calculate the temperature T _est of 20. Here, the detection rate α is preset in the calculation unit 4.

Further, the calculation unit 4 calculates the absolute amount or concentration of the absorber ABS based on the transmittance τ(λ ₂ ).

FIG. 3 is a flowchart for explaining the detection method according to the first embodiment for detecting the temperature of the object 20 and/or the absolute amount or concentration of the absorber ABS.

With reference to FIG. 3, when the operation of detecting the temperature of the target object 20 and/or the absolute amount or concentration of the absorber ABS is started, the detectors 2 and 3 respectively detect the spectral irradiance I(λ ₂ , T). ), I(λ ₃ , T) is detected (step S1), and the detected spectral irradiance I(λ ₂ , T), I(λ ₃ , T) is output to the calculation unit 4.

The calculation unit 4 receives the spectral irradiances I(λ ₂ , T) and I(λ ₃ , T) from the detectors 2 and 3, respectively.

Then, the calculation unit 4 detects the approximate value R _est of the ratio of the black body spectral radiance from the brightness ratio parameter 43 (step S2).

Then, the calculation unit 4 calculates an approximate value of the ratio of the spectral irradiances I(λ ₂ , T), I(λ ₃ , T), the emissivity ε(λ ₂ ), ε(λ ₃ ) and the black body spectral radiance. Substituting R _est into the equation (10), the transmittance ratio τ(λ ₂ )/τ(λ ₃ ) is calculated (step S3).

Subsequently, the calculation unit 4, the ratio of the transmittance _{τ (λ 2) / τ (} λ 3) and extinction coefficient _{ε a (λ 2), ε} a (λ 3) transmission based on tau to (lambda ₂₎ Calculate (step S4). More specifically, the calculation unit 4 detects the transmittance corresponding to the transmittance ratio τ(λ ₂ )/τ(λ ₃ ) based on the transmittance calculation table 42, thereby calculating the transmittance ratio τ. The transmittance τ(λ ₂ ) is calculated from (λ ₂ )/τ(λ ₃ ). Further, the calculation unit 4 substitutes the reciprocal of the transmittance ratio τ(λ ₂ )/τ(λ ₃ ) and the extinction coefficients ε _a (λ ₂ ), ε _a (λ ₃ ) into the equation (5) for transmission. Calculate the rate τ(λ ₂ ).

After step S4, the calculation unit 4 substitutes the detection ratio α, the spectral irradiance I(λ ₂ , T), the transmittance τ(λ ₂ ) and the emissivity ε(λ ₂ ) into the formula (1) to obtain black. The body spectral radiance B(λ ₂ , T) is calculated (step S5).

Then, the calculation unit 4 substitutes the calculated black body spectral radiance B(λ ₂ , T) into the equation (2) to calculate the temperature T _est (step S6).

Subsequently, the calculation unit 4 calculates the absolute amount or concentration of the absorber ABS based on the transmittance τ(λ ₂ ) (step S7). This completes a series of operations.

Equation (10), the ratio tau (lambda ₂₎ of the transmittance with respect to transmittance _{τ (λ 3) τ (λ} 2) / τ (λ 3) is a formula for calculating a relative transmittance tau (lambda ₂₎ The ratio τ(λ ₃ )/τ(λ ₂ ) of the transmittance τ(λ ₃ ) is calculated by the formula (1) for the spectral irradiance I(λ ₂ ,T) and the spectral irradiance I(λ ₃ ,T). It is derived from the equation (1) and the following equation.

そして、透過率τ（λ_２）についての式（４）と、透過率τ（λ_３）についての式（４）とにより、透過率の比τ（λ_３）／τ（λ_２）から透過率τ（λ_３）を算出する次式が得られる。

Then, using the formula (4) for the transmittance τ(λ ₂ ) and the formula (4) for the transmittance τ(λ ₃ ), the transmittance is calculated from the ratio τ(λ ₃ )/τ(λ ₂ ). The following equation for calculating the rate τ(λ ₃ ) is obtained.

従って、図３に示す検出方法においては、算出部４は、ステップＳ３において、式（１１）によって透過率の比τ（λ_３）／τ（λ_２）を算出し、ステップＳ４において、式（１２）によって、算出した透過率の比τ（λ_３）／τ（λ_２）に基づいて透過率τ（λ_３）を算出してもよい。この場合、ステップＳ５において、検出割合α、分光放射照度Ｉ（λ_３，Ｔ）、透過率τ（λ_３）および放射率ε（λ_３）を、分光放射照度Ｉ（λ_３，Ｔ）についての式（１）に代入して黒体分光放射輝度Ｂ（λ_３，Ｔ）を算出し、ステップＳ６において、算出した黒体分光放射輝度Ｂ（λ_３，Ｔ）を式（２）に代入して温度Ｔ_ｅｓｔを算出することができる。この場合、算出部４は、ステップＳ７において、透過率τ（λ_３）に基づいて、吸収体ＡＢＳの絶対量または濃度を算出する。なお、透過率の比τ（λ_３）／τ（λ_２）に基づいて透過率τ（λ_３）を算出する場合、算出部４は、透過率の比τ（λ_３）／τ（λ_２）および吸光係数の比ε_ａ（λ_２）／ε_ａ（λ_３）を式（１２）に代入して透過率τ（λ_３）を算出してもよいし、透過率の比τ（λ_３）／τ（λ_２）と透過率τ（λ_３）との関係を含む透過率算出テーブルに基づいて透過率の比τ（λ_３）／τ（λ_２）から透過率τ（λ_３）を算出してもよい。

Therefore, in the detection method shown in FIG. 3, the calculation unit 4 calculates the transmittance ratio τ(λ ₃ )/τ(λ ₂ ) by the equation (11) in step S3, and then in step S4, the equation ( 12), the transmittance τ(λ ₃ ) may be calculated based on the calculated transmittance ratio τ(λ ₃ )/τ(λ ₂ ). In this case, in step S5, the detection ratio α, the spectral irradiance I(λ ₃ , T), the transmittance τ(λ ₃ ) and the emissivity ε(λ ₃ ) are calculated with respect to the spectral irradiance I(λ ₃ , T). To calculate the black body spectral radiance B(λ ₃ , T), and in step S6, substitute the calculated black body spectral radiance B(λ ₃ ,T) into the formula (2). Then, the temperature T _est can be calculated. In this case, the calculation unit 4 calculates the absolute amount or concentration of the absorber ABS based on the transmittance τ(λ ₃ ) in step S7. When calculating the transmittance τ(λ ₃ ) based on the transmittance ratio τ(λ ₃ )/τ(λ ₂ ), the calculation unit 4 calculates the transmittance ratio τ(λ ₃ )/τ(λ ₂ ) and the extinction coefficient ratio ε _a (λ ₂ )/ε _a (λ ₃ ) may be substituted into equation (12) to calculate the transmittance τ(λ ₃ ), or the transmittance ratio τ( Based on the transmittance calculation table including the relationship between λ ₃ )/τ(λ ₂ ) and the transmittance τ(λ ₃ ), the transmittance ratio τ(λ ₃ )/τ(λ ₂ ) to the transmittance τ(λ ₃ ) may be calculated.

In the first embodiment, the operation of detecting the temperature of object 20 and/or the absolute amount or concentration of absorber ABS may be executed by software. In this case, the calculation unit 4 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory).

The ROM receives the spectral irradiance I(λ ₂ , T) and the spectral irradiance I(λ ₃ , T) from the detectors 2 and 3, respectively, in step S1-1, and the emissivity via the input device (keyboard or the like). A program Prog_A including step S1-2 that receives ε(λ ₂ ), ε(λ ₃ ) and extinction coefficients ε _a (λ ₂ ), ε _a (λ ₃ ) and steps S2 to S7 shown in FIG. Store. The ROM also stores the transmittance calculation table 42 and the brightness ratio parameter 43 shown in FIG. The RAM has the spectral irradiances I(λ ₂ , T), I(λ ₃ , T), emissivity ε(λ ₂ ), ε(λ ₃ ) and extinction coefficient ε _a (λ ₂ ), which are received by the CPU. ε _a (λ ₃ ), the approximate value R _est of the ratio of the black body spectral radiance detected by the CPU, the transmittance ratio τ(λ ₂ )/τ(λ ₃ ) calculated by the CPU, and the calculation The transmittance τ(λ ₂ ) and the temperature T _est calculated by the CPU are temporarily stored.

The CPU reads the program Prog_A from the ROM, sequentially executes steps S1-1, S1-2, S2 to S7 of the read program Prog_A, and then performs the temperature of the object 20 and/or the absorber ABS by the method described above. To detect the absolute amount or concentration of.

In this case, the CPU that detects the approximate value R _est of the black body spectral radiance ratio constitutes a “detection unit”, and the transmittance ratio τ(λ ₂ )/τ(λ ₃ ), the transmittance τ(λ ₂ ) and the CPU that calculates the temperature T _est form “calculation means”. Further, spectral irradiances I(λ ₂ , T), I(λ ₃ , T), emissivity ε(λ ₂ ), ε(λ ₃ ) and extinction coefficients ε _a (λ ₂ ), ε _a (λ ₃ ) The CPU that accepts "constitutes" constitutes "accepting means".

Further, the program Prog_A may be recorded in a recording medium (for example, CD and DVD) and distributed. In this case, the computer (CPU) reads the program Prog_A from the recording medium and executes it to detect the temperature of the object 20 and/or the absolute amount or concentration of the absorber ABS. Therefore, a CD, a DVD, or the like in which the program Prog_A is recorded is a computer (CPU) readable recording medium in which the program Prog_A is recorded.

As described above, in the first embodiment, the spectral irradiances I(λ ₂ , T), I(λ ₃ , T) detected by the detectors ₂ , ₃ and the known emissivity ε(λ ₂ ), ε are known. (Λ ₃ ), known extinction coefficients ε _a (λ ₂ ), ε _a (λ ₃ ), and the approximate value R _est of the ratio of the blackbody spectral radiance detected from the brightness ratio parameter 43 are used. The detection method according to the first embodiment uses the parameters described above to calculate one of the transmittance τ(λ ₂ ) and the transmittance τ(λ ₃ ), and calculates the calculated transmittance (transmittance τ(λ Any one of ₂ ) and the transmittance τ(λ ₃ )) may be used to calculate the temperature of the object 20 and/or the absolute amount or concentration of the absorber ABS.

In this way, the infrared detection device 10 functions as a radiation thermometer that calculates the temperature of the object 20 and/or a gas sensor that calculates the absolute amount or concentration of the absorber ABS.

[Selection method of wavelengths λ ₂ and λ ₃ ]
A method of selecting the wavelengths λ ₂ and λ ₃ based on the accuracy rating of the radiation thermometer and the measurement range of the temperature of the object 20 will be described.

As described above, in the first embodiment, the ratio of the black body spectral radiance is approximated to a certain value R _est , and the ratio of the spectral irradiances I(λ ₂ , T) and I(λ ₃ , T) is calculated. The temperature of the object 20 is calculated.

Spectral irradiance I(λ ₂ , T) detected by the infrared detection device 10 having the function of a radiation thermometer, transmittance τ _est (λ ₂ ) calculated by the infrared detection device 10, and temperature calculated by the infrared detection device 10. T _est1 satisfies the following equation.

上述した方法によって、分光放射照度Ｉ（λ_２，Ｔ），Ｉ（λ_３，Ｔ）の比および赤外線検出装置１０に設定する黒体分光放射輝度の比の近似値Ｒ_ｅｓｔから、透過率の比τ_ｅｓｔ（λ_３）／τ_ｅｓｔ（λ_２）を算出すると、次式が得られる。

By the above-mentioned method, the transmittance of the ratio of the spectral irradiance I(λ ₂ , T), I(λ ₃ , T) and the approximate value R _est of the ratio of the black body spectral radiance set in the infrared detection device 10 When the ratio τ _est (λ ₃ )/τ _est (λ ₂ ) is calculated, the following equation is obtained.

式（１４）において、近似値Ｒ_ｅｓｔは、対象物２０の温度の測定範囲において算出されるので、対象物２０の温度の測定範囲における値をＲ_ｅｓｔとして用いればよい。例えば、Ｒ_ｅｓｔは、平均値でもよいし、中央値でもよい。

In Expression (14), the approximate value R _est is calculated in the measurement range of the temperature of the object 20, and thus the value in the measurement range of the temperature of the object 20 may be used as R _est . For example, R _est may be an average value or a median value.

By applying the equations (1) and (5) to the equation (14), the following equation is obtained.

式（１５）において、Ｒ（Ｔ）は、波長λ_３における黒体分光放射輝度Ｂ（λ_３，Ｔ）と波長λ_２における黒体分光放射輝度Ｂ（λ_２，Ｔ）との比（＝Ｂ（λ_３，Ｔ）／Ｂ（λ_２，Ｔ））である。

The ratio of the equation (15), R (T) is blackbody spectral radiance B at a wavelength λ ₃ (λ _3, T) and the black body spectral radiance B at a wavelength _{λ 2 (λ 2, T)} (= B(λ ₃ , T)/B(λ ₂ , T)).

Formula (15) is the ratio R(T) of the black body spectral radiance B(λ ₃ , T) and the black body spectral radiance B(λ ₂ , T), and the black body set in the infrared detection device 10. The quotient of the spectral radiance ratio and the approximate value R _est indicates that it is an error factor of the transmittance τ _est (λ ₂ ) calculated by the infrared detection device 10.

Substituting equation (15) into equation (13) and applying equation (2), the following equation is obtained.

式（１６）は、赤外線検出装置１０が検出する分光放射照度Ｉ（λ_２，Ｔ），Ｉ（λ_３，Ｔ）、検出割合α、および既知である放射率ε（λ_２），ε（λ_３）によって対象物２０の温度Ｔ_ｅｓｔ１を算出できことを示す。

Formula (16) is the spectral irradiance I(λ ₂ , T), I(λ ₃ , T) detected by the infrared detection device 10, the detection ratio α, and the known emissivity ε(λ ₂ ), ε( It is shown that the temperature T _{est1 of the} object 20 can be calculated by λ ₃ ).

On the other hand, when the equations (15) and (1) are substituted into the equation (13), the following equation is obtained.

そして、式（１７）を、実施の形態１の前提に従って、式（１４）の下で近似的に解くと、次式が得られる。

Then, when the equation (17) is approximately solved under the equation (14) according to the premise of the first embodiment, the following equation is obtained.

この場合、上述した条件１）および条件２）を考慮した。条件１）および条件２）によると、Ｒ（Ｔ）は、１に近く、温度依存性の小さい値であり、赤外線検出装置１０に設定する黒体分光放射輝度の比Ｒ_ｅｓｔで近似できる。

In this case, the conditions 1) and 2) described above were considered. According to the conditions 1) and 2), R(T) is close to 1 and has a small temperature dependence, and can be approximated by the ratio R _est of the black body spectral radiance set in the infrared detection device 10.

In the design of the radiation thermometer, it is necessary to define the minimum temperature T _min and the maximum temperature T _max as the measurement range of the temperature of the object 20. Further, the radiation thermometer needs to be able to calculate the temperature with higher accuracy than _a certain accuracy rating Ta. That is, the detection wavelength of the radiation thermometer must be designed so as to satisfy the accuracy rating Ta for a certain measurement range. The accuracy rating T _a defines the accuracy of the calculated temperature.
(Calculation temperature 1 and accuracy rating)
_Let T _est1 in the equation (18) be the calculated temperature 1 and define the calculation error 1 by (T _est1 −T). In this case, the second term on the right side of Expression (18) becomes a calculation error.

That is, as shown in equation (19), the absolute value of the calculated error in accuracy rating of the radiation thermometer absolute value of _{(T a),} the measurement range of the temperature of the object _{20 ([T min ~T max]} ) ( It is necessary to set the value larger than | _Test1- T|).

検出波長λ_２，λ_３は、対象物２０の温度の測定範囲において、式（１９）に示す｜Ｔ_ｅｓｔ１−Ｔ｜＜Ｔ_ａを満たす検出波長から選択すればよい。具体的には、使用可能なλ_２，λ_３の組み合わせで｜Ｔ_ｅｓｔ１−Ｔ｜を算出し、これがＴ_ａより小さくなる組み合わせを選択すればよい。
（算出温度２と精度定格）
上述した方法によって、放射温度計が算出する対象物２０の温度（Ｔ_ｅｓｔ１）を算出した後に、Ｔ_ｅｓｔ１に補正を行うことで、より高精度に対象物２０の温度（Ｔ）を算出することができる。例えば、式（２０）におけるＴ_ｅｓｔ２を算出温度２とし、算出誤差２を（Ｔ_ｅｓｔ２−Ｔ）と定義する。

Detection wavelength lambda _2, lambda _3, in the measurement range of the temperature of the object 20, shown in equation (19) _| may be selected from detection wavelength satisfying _{<T a} | _T est1 -T. Specifically, ₂ available lambda, lambda ₃ in combination _{| T est1} -T | is calculated and may be selected a combination which is less than _{T a.}
(Calculation temperature 2 and accuracy rating)
By calculating the temperature (T _est1 ) of the target object 20 calculated by the radiation thermometer by the above-described method, then correcting the T _est1 to calculate the temperature (T) of the target object 20 with higher accuracy. You can For example, _Test2 in Expression (20) is _defined as the calculated temperature 2, and the calculation error 2 is defined as ( _Test2- T).

式（２０）は、式（１８）の右辺の第２項が十分小さい場合に成立する、式（１８）に基づく対象物２０の温度（Ｔ）の算出式である。

Formula (20) is a formula for calculating the temperature (T) of the object 20 based on formula (18), which holds when the second term on the right side of formula (18) is sufficiently small.

According to equation (21), the absolute value of the calculated error in accuracy rating of the radiation thermometer absolute value of _{(T a),} the measurement range of the temperature of the object _{20 ([T min ~T max]} ) (| T est2 - It is necessary to set the value larger than T|).

補正後の放射温度計が算出する対象物２０の温度の算出には、必ずしも式（２０）を使用する必要はなく、シミュレーションによって補正関数を定めてもよい。

The calculation of the temperature of the object 20 calculated by the corrected radiation thermometer does not necessarily need to use the equation (20), and the correction function may be determined by simulation.

Detection wavelength lambda _2, lambda _3, in the measurement range of the temperature of the object 20, shown in equation (21) _| may be selected from detection wavelength satisfying _{<T a} | _T est2 -T. Specifically, ₂ available lambda, lambda ₃ in combination _{| T est2} -T | is calculated and may be selected a combination which is less than _{T a.}

FIG. 4 is a flowchart showing a selection method for selecting the _two wavelengths λ ₂ and λ ₃ based on the accuracy rating of the radiation thermometer and the measurement range of the temperature of the object.

Referring to FIG. 4, when the operation of selecting the _two wavelengths λ ₂ and λ ₃ is started, the wavelength selecting unit 44 causes the approximate value R _est of the ratio of the black body spectral radiance and the black body spectral radiance B. The ratio B(λ ₃ , T)/B(λ ₂ , T) of the black body spectral radiance B(λ ₃ , T) to (λ ₂ , T) and the ratio ε _a (λ ₃ )/ε _{a of the} extinction coefficient. The calculated temperature T _est1 of the object 20 is calculated using the calculation error ΔT _est calculated based on (λ ₂ ) (step S11). That is, the wavelength selection unit 44 calculates the calculated temperature T _est1 by the equation (18).

Then, the wavelength selection unit 44 calculates the absolute value | _Test1- T| of the difference between the calculated temperature _Test1 and the temperature T of the object 20 (step S12).

After that, the wavelength selection unit 44 sets the absolute value |T _est1 −T| to be smaller than the absolute value |T _a | of the accuracy rating T _a in the measurement range (T _{min to} T _max ) of the temperature of the object 20. Two wavelengths λ ₂ and λ ₃ are selected (step S13). This completes the operation of selecting the _two wavelengths λ ₂ and λ ₃ .

FIG. 5 is a flowchart showing another selection method for selecting the _two wavelengths λ ₂ and λ ₃ based on the accuracy rating of the radiation thermometer and the measurement range of the temperature of the object.

Referring to FIG. 5, when the operation of selecting the _two wavelengths λ ₂ and λ ₃ is started, the wavelength selection unit 44 causes the detection ratio α, the emissivity ε(λ ₂ ), ε(λ ₃ ), and the spectroscopy. Based on the approximate value R _est of the ratio of the irradiances I(λ ₂ , T), I(λ ₂ , T) and the black body spectral radiance, the extinction coefficient ratio ε _a (λ ₃ )/ε _a (λ ₂ ) _{Is used} to calculate the parallel root of the estimated transmittance ratio, and the calculated temperature T _est1 of the object 20 is calculated (step S21). That is, the wavelength selection unit 44 calculates the calculated temperature T _est1 by the equation (16).

Then, the wavelength selection unit 44 calculates the calculated temperature _{T est2} by correcting the calculated temperature _{T est1} (step S22). That is, the wavelength selection unit 44 calculates the calculated temperature _{T est2} the calculated calculated temperature _{T est1} into Equation (20). In this case, the wavelength selection unit 44 holds in advance a brightness table indicating the relationship between the temperature and the wavelength and the black body spectral radiance, and the black body spectral radiance B(λ ₂ , T _est1 ), B(λ ₃ , T _est1 ), and based on the detected black body spectral radiance B(λ ₂ , T _est1 ), B(λ ₃ , T _est1 ) of the black body spectral radiance _{Calculate the} ratio R(T _est1 )=B(λ ₃ , T _est1 )/B(λ ₂ , T _est1 ).

After step S22, the wavelength selection unit 44 calculates the absolute value | _Test2- T| of the difference between the calculated temperature _Test2 and the temperature T of the object 20 (step S23).

Thereafter, the wavelength selection unit 44, the measurement range of the temperature of the object 20 _(T min _{~T max),} the absolute value _{| T est2} -T | is the absolute value of the accuracy rating _{T a} | _{T a} | smaller than as To select _two wavelengths λ ₂ and λ ₃ (step S24). This completes the operation of selecting the _two wavelengths λ ₂ and λ ₃ .

The wavelength selection unit 44 selects two wavelengths λ ₂ and λ ₃ according to the flowchart shown in FIG. 4 or the flowchart shown in FIG. 5, and outputs the selected two wavelengths λ ₂ and λ ₃ to the calculation unit 4.

In the first embodiment, the operation of selecting the _two wavelengths λ ₂ and λ ₃ based on the accuracy rating of the radiation thermometer and the measurement range of the temperature of the object may be executed by software. In this case, the calculation unit 4 includes a CPU, ROM and RAM.

The ROM receives the spectral irradiance I(λ ₂ , T) and the spectral irradiance I(λ ₃ , T) from the detectors 2 and 3, respectively, at step S1-1, and the emissivity via the input device (keyboard or the like). A program Prog_B including step S1-2 for receiving ε(λ ₂ ), ε(λ ₃ ) and extinction coefficients ε _a (λ ₂ ), ε _a (λ ₃ ), and steps S11 to S13 shown in FIG. 4. Alternatively, step S1-1 of receiving the spectral irradiance I(λ ₂ , T) and the spectral irradiance I(λ ₃ , T) from the detectors 2 and 3, respectively, and the emissivity ε( via the input device (keyboard or the like). A program Prog_C including step S1-2 for receiving λ ₂ ), ε(λ ₃ ) and extinction coefficients ε _a (λ ₂ ), ε _a (λ ₃ ) and steps S21 to S24 shown in FIG. 5 is stored. .. The ROM also stores the transmittance calculation table 42 and the brightness ratio parameter 43 shown in FIG. The RAM has the spectral irradiances I(λ ₂ , T), I(λ ₃ , T), emissivity ε(λ ₂ ), ε(λ ₃ ) and extinction coefficient ε _a (λ ₂ ), which are received by the CPU. ε _a (λ ₃ ), the approximate value R _est of the ratio of the black body spectral radiance detected by the CPU, the ratio ε _a (λ ₃ )/ε _a (λ ₂ ) of the extinction coefficient calculated by the CPU, The calculated calculation error ΔT _est , the calculated temperatures T _est1 and T _est2 calculated by the CPU, and the absolute values |T _est1 −T| and |T _est2 −T| calculated by the CPU are temporarily stored.

The CPU reads the program Prog_B or the program Prog_C from the ROM, executes the read program Prog_B or the program Prog_C, and selects the _two wavelengths λ ₂ and λ ₃ by the method described above.

In this case, the CPU that detects the approximate value R _est of the ratio of the black body spectral radiance constitutes “detection means”, and the ratio of extinction coefficients ε _a (λ ₃ )/ε _a (λ ₂ ), the calculated temperature T. _The CPU that calculates _est1 , T _est2 , and the absolute values |T _est1 −T|, |T _est2 −T| configures “calculating means”. Further, spectral irradiances I(λ ₂ , T), I(λ ₃ , T), emissivity ε(λ ₂ ), ε(λ ₃ ) and extinction coefficients ε _a (λ ₂ ), ε _a (λ ₃ ) The CPU that accepts "constitutes" constitutes "accepting means".

Further, the program Prog_B or the program Prog_C may be recorded in a recording medium (for example, CD and DVD) and distributed. In this case, the computer (CPU) reads the program Prog_B or the program Prog_C from the recording medium and executes the program to select the _two wavelengths λ ₂ and λ ₃ . Therefore, a CD, a DVD, or the like in which the program Prog_B or the program Prog_C is recorded is a computer (CPU) readable recording medium in which the program Prog_B or the program Prog_C is recorded.

As described above, can be calculated calculated temperature _{T est1} of the object 20 by equation (16) can be calculated to calculate the temperature _{T est2} object 20 by equation (20). Therefore, in the first embodiment, the temperature of the object 20 may be calculated using the equation (16) or the equation (20).

FIG. 6 is a flowchart showing a detection method for detecting the temperature of the target object 20 in the first embodiment. The flowchart shown in FIG. 6 is the same as the flowchart shown in FIG. 3 except that steps S3 to S7 of the flowchart shown in FIG. 3 are replaced with steps S31 and S32.

Referring to FIG. 6, when the operation of detecting the temperature of object 20 is started, calculation unit 4 sequentially executes steps S1 and S2 described above. Then, after step S2, the calculation unit 4 causes the spectral irradiances I(λ ₂ , T), I(λ ₃ , T), the emissivity ε(λ ₂ ), ε(λ ₃ ), and the extinction coefficient ratio ε. _{Based on a} (λ ₃ )/ε _a (λ ₂ ) and the approximate value R _est of the ratio of the black body spectral radiance, a root including the ratio ε _a (λ ₃ )/ε _a (λ ₂ ) of the extinction coefficient is found. The square root of the estimated transmittance ratio is calculated using the calculated temperature T _est1 of the object 20 (step S31). That is, the calculation unit 4 calculates the calculated temperature T _est1 by the formula (16).

The calculation unit 4 calculates the calculated temperature _{T est2} by correcting the calculated temperature _{T est1} (step S32). That is, the calculating unit 4 calculates the calculated temperature _{T est2} by correcting the calculated temperature _{T est1} by equation (20). As a result, the operation of detecting the temperature of the object 20 ends.

The detection method for detecting the temperature of the target object 20 is to calculate the calculated temperature T _est1 of the target object 20 according to steps S1, S2, and S31 shown in FIG. 6, and use the calculated calculated temperature T _est1 as the temperature of the target object 20. _{Alternatively} , the calculated temperature T _est2 of the target object 20 may be calculated according to steps S1, S2, S31, and S32 shown in FIG. 6, and the calculated calculated temperature T _est2 may be detected as the temperature of the target object 20. Good.

Then, by detecting the calculated temperature T _est2 as the temperature of the object 20, than the case of detecting the calculated temperature T _est1 as the temperature of the object 20, the temperature of the object 20 can be detected with high accuracy.

Further, in the first embodiment, the operation of detecting the temperature of the object 20 may be executed by software. In this case, the calculation unit 4 includes a CPU, ROM and RAM.

The ROM receives the spectral irradiance I(λ ₂ , T) and the spectral irradiance I(λ ₃ , T) from the detectors 2 and 3, respectively, at step S1-1, and the emissivity via the input device (keyboard or the like). Step S1-2 of receiving ε(λ ₂ ), ε(λ ₃ ) and extinction coefficients ε _a (λ ₂ ), ε _a (λ ₃ ), and steps S2, S31, and S32 shown in FIG. Store the program Prog_D. The ROM also stores the transmittance calculation table 42 and the brightness ratio parameter 43 shown in FIG. The RAM has the spectral irradiances I(λ ₂ , T), I(λ ₃ , T), emissivity ε(λ ₂ ), ε(λ ₃ ) and extinction coefficient ε _a (λ ₂ ), which are received by the CPU. ε _a (λ ₃ ), an approximate value R _est of the ratio of black body spectral radiance detected by the CPU, a ratio of extinction coefficients ε _a (λ ₃ )/ε _a (λ ₂ ), and a ratio of black body spectral radiance. The "root including the extinction coefficient ratio ε _a (λ ₃ )/ε _a (λ ₂ )" calculated by the CPU based on the approximate value R _est of the temperature and the temperatures T _est1 and T _est2 calculated by the CPU are temporarily Remember.

The CPU reads the program Prog_D from the ROM and sequentially executes steps S1-1, S1-2, S2, S31 or steps S1-1, S1-2, S2, S31, S32 of the read program Prog_C, The temperature of the object 20 is detected by the method described above.

In this case, the CPU that detects the approximate value R _est of the ratio of the black body spectral radiance constitutes “detecting means”, and the ratio of the extinction coefficients ε _a (λ ₃ )/ε _a (λ ₂ ) and the black body spectrum. CPU for calculating “root including extinction coefficient ratio ε _a (λ ₃ )/ε _a (λ ₂ )” and CPU for calculating temperatures T _est1 and T _est2 based on the approximate value R _est of the ratio of radiances Constitutes "calculation means". Further, spectral irradiances I(λ ₂ , T), I(λ ₃ , T), emissivity ε(λ ₂ ), ε(λ ₃ ) and extinction coefficients ε _a (λ ₂ ), ε _a (λ ₃ ) The CPU that accepts "constitutes" constitutes "accepting means".

Further, the program Prog_D may be recorded in a recording medium (for example, CD and DVD) and distributed. In this case, the computer (CPU) reads the program Prog_D from the recording medium and executes it to detect the temperature of the object 20. Therefore, a CD, a DVD, or the like in which the program Prog_D is recorded is a computer (CPU) readable recording medium in which the program Prog_D is recorded.
(Radiation thermometer corrected for the effect of water vapor)
When the ratio (ε(λ+0.5 μm)/ε(λ)) of the extinction coefficient by the absorber ABS is 1.5 or more or 0.67 or less, the detection wavelength λ _{2 of the} radiation thermometer is based on the second embodiment. , Λ ₃ is designed.

The wavelength (λ) is a wavelength belonging to a certain wavelength range. For example, in the extinction coefficient of water vapor, the above relationship is satisfied when the wavelength λ belongs to 6.5 to 9.5 μm or 11 to 15.5 μm.

For example, in an environment where water vapor is absorbed, a radiation thermometer that meets the accuracy rating ±2°C and measures the object 20 at -50 to 50°C is designed. According to the first embodiment, by using the equations (16) and (20), the accuracy rating is guaranteed when the detection wavelengths λ ₂ and λ ₃ are in the ranges of 6.5 to 10 μm and 11 to 15.5 μm. be able to.

In addition, a radiation thermometer that measures the object 20 at −20 to 120° C. and satisfies the accuracy rating of ±2° C. in an environment where water vapor is absorbed is designed. According to the second embodiment, by using the equations (18) and (22), the accuracy rating can be guaranteed in the detection wavelengths λ ₂ and λ ₃ in the range of 6.5 to 10 μm.

Furthermore, a radiation thermometer that measures the object 20 at 100 to 1000° C. and meets the accuracy rating of ±2° C. in an environment where water vapor is absorbed is designed. According to the second embodiment, by using the equations (16) and (20), the accuracy rating can be guaranteed in the detection wavelengths λ ₂ and λ ₃ in the range of 6.5 to 10 μm.
(Effect of using a detection wavelength longer than the peak wavelength)
When selecting the detection wavelength from the peak wavelength of the Wien's displacement law, it is possible to design a radiation thermometer that satisfies the same accuracy rating ±2°C and can measure a wider temperature range.

For example, a radiation thermometer is designed to measure the object 20 at −20 to 120° C. in an environment where water vapor is absorbed. According to the temperature of the target object 20 and the Wien's displacement law, the peak wavelength (λ _max ) of the black body spectral radiance is 7.4 to 11.4 μm. Therefore, the detection wavelengths λ ₂ and λ ₃ are set in the range of 11.4 to 16 μm on the long wavelength side of the peak wavelength. By using the equations (14) and (18) based on the second embodiment, the accuracy rating ±2°C can be guaranteed.

Further, a radiation thermometer that measures the object 20 at -50 to 1000° C. under the absorption environment of water vapor is designed. According to the temperature of the target object 20 and the Wien's displacement law, the peak wavelength (λ _max ) of the black body spectral radiance is 2.3 to 13 μm. Therefore, the detection wavelengths λ ₂ and λ ₃ are set in the range of 13 to 15.5 μm on the long wavelength side of the peak wavelength. By using the equations (14) and (18) based on the second embodiment, the accuracy rating ±2°C can be guaranteed.

[Temperature calculation accuracy]
It will be described that the infrared detector 10 according to the first embodiment can calculate the temperature with high accuracy in the presence of the absorber ABS.
(Setting of infrared detector)
First, the infrared detector 10 is prepared in advance according to the first embodiment. Specific examples in the case where the absorber ABS is water vapor will be shown below.

For simplicity, the detection rate α is 0.1 and the emissivity ε is 1. The temperature of the target object 20 is 0 to 100°C.

FIG. 7 is a diagram showing the relationship between the transmittance and the wavelength. In FIG. 7, the vertical axis represents the transmittance and the horizontal axis represents the wavelength.

Referring to FIG. 7, water (H ₂ O), oxygen (O ₂ ), ozone (O ₃ ), and carbon dioxide (CO ₂ ) are shown in association with absorption wavelengths as absorption molecules existing in the atmosphere. ing.

Within the range of the window of the atmosphere shown in FIG. 7, the detection wavelength λ ₂ is 13.0 μm and the detection wavelength λ ₃ is 13.5 μm. The brightness ratio parameter 43 and the transmittance calculation table 42 are preset in the calculator 4. Further, the value of the brightness ratio parameter 43 is set to 0.947. For example, since the ratio of the black body spectral radiance when the temperature of the black body is 0 to 100° C. is 0.930 to 0.965, the ratio of the black body spectral radiance changes by about 3.6%.

The transmittance calculation table 42 refers to the ratio of extinction coefficients ε _a (λ ₂ )/ε _a (λ ₃ ) based on the formula (5) for calculating the transmittance from the transmittance ratio, for example, referring to FIG. And create it as 0.5. This is the ratio of the extinction coefficients of water vapor at wavelengths 13.0 μm and 13.5 μm.
(Calculation accuracy according to the first embodiment)
The calculation accuracy of the temperature in the first embodiment will be described based on the simulation. First, we created a simulation task. The transmittances τ(λ ₂ )=0.50 and τ(λ ₃ )=0.25 that match the adopted extinction coefficient ratio of 0.5 are set, and the spectra corresponding to the respective temperatures are set based on the equation (1). Irradiances I (13.0 μm, T) and I (13.5 μm, T) were calculated. This spectral irradiance was defined as the spectral irradiance detected by the detectors 2 and 3, and the temperature of the object 20 was calculated based on the first embodiment.

First, the temperature of the object 20 was calculated by the equation (16) from the ratio of the spectral irradiance I (13.0 μm, T), I (13.5 μm, T) and the ratio of the spectral radiance 0.947.

FIG. 8 is a diagram showing a temperature difference between the set temperature of the target object 20 and the calculated temperature obtained by the simulation. In FIG. 8, the vertical axis represents the difference between the calculated temperature and the temperature of the target object 20, and the horizontal axis represents the temperature of the target object 20.

Referring to FIG. 8, even if the transmittance depends on the wavelength, the calculated temperature falls within an error of about −1.3° C. to +2.1° C. with respect to the temperature of the object 20. That is, assuming that the detection wavelength λ ₂ is 13.0 μm, the detection wavelength λ ₃ is 13.5 μm, and the ratio of the black body spectral radiance at these wavelengths is 0.947, the target object 20 has a temperature of 0 to 100° C. Within the temperature range, the temperature can be calculated with the accuracy of −1.3° C. to +2.1° C. by the equation (16).

Next, the corrected calculated temperature was calculated by the equation (20) from the calculated temperature and the spectral radiance ratio of 0.947.

FIG. 9 is a diagram showing a temperature difference between the set temperature of the target object 20 and the corrected calculated temperature obtained by the simulation. In FIG. 9, the vertical axis represents the difference between the corrected calculated temperature and the temperature of the target object 20, and the horizontal axis represents the temperature of the target object 20.

With reference to FIG. 9, even when the transmittance depends on the wavelength, the calculated temperature after correction falls within an error of about −0.1° C. to +0.04° C. with respect to the temperature of the object 20. That is, assuming that the detection wavelength λ ₂ is 13.0 μm, the detection wavelength λ ₃ is 13.5 μm, and the ratio of the black body spectral radiance at these wavelengths is 0.947, the target object 20 has a temperature of 0 to 100° C. Within the temperature range, the temperature can be calculated with the accuracy of −0.1° C. to +0.04° C. by the formula (20).

[Effects of First Embodiment]
The effects of the first embodiment will be described.
(Effects of radiation thermometer)
The effect of using the infrared detection device 10 according to the first embodiment as a radiation thermometer will be described.

In the conventional monochromatic method, the temperature is calculated by setting the transmittance to a value that is predicted in advance. Therefore, if the transmittance differs from the value, a calculation error occurs in the temperature. For example, assume that a monochromatic radiation thermometer that detects infrared rays with a detection wavelength of 8.5 μm is used, and that the transmittance should be set to 0.77 when the transmittance should be set to 0.77. That is, the radiation thermometer estimates the spectral radiance of the object 20 to be 0.77 times the original value. Under this condition, when the object 20 at 35° C. is detected according to the equation (1), the calculated temperature becomes about 21° C., which causes a large error. Further, in the conventional two-color method, since the transmittance has wavelength dependency, it is not possible to calculate temperature with high accuracy. In the conventional two-color method, the temperature is calculated on the assumption that the transmittance does not depend on the wavelength. Therefore, when the actual transmittance has the wavelength dependency, a calculation error occurs in the temperature.

For example, using a conventional dichroic radiation thermometer that detects infrared rays having a detection wavelength of 8.5 μm and infrared rays having a detection wavelength of 13.0 μm, the transmittance is τ(8.5 μm)=0.77 and τ(13 .0)=0.5, the case where the temperature of the target object 20 is calculated is assumed. Under this condition, if the ratio of the spectral irradiance is regarded as the ratio of Planck's equation and the temperature is calculated, the object 20 at 35° C. is calculated as 137° C.

On the other hand, as shown in the simulation and FIGS. 8 and 9, the infrared detection device 10 according to the first embodiment can calculate an accurate temperature even when the transmittance depends on the wavelength. That is, the infrared detection device 10 according to the first embodiment has a transmittance correction function not found in conventional radiation thermometers.

In the first embodiment, the transmittance correction function can be added by using the fact that the temperature dependence of the ratio of the black body spectral radiance is reduced for the two wavelengths in the long wavelength region. Thereby, for example, in an environment where the transmittance greatly changes due to the influence of water vapor (for example, outdoors in bad weather such as rain or fog, a bathroom, etc.), it is possible to improve the detection performance of humans or animals. That is, it is possible to detect a person or an animal from a greater distance in bad weather and to detect an accident in a bathroom early.

Further, according to the infrared detection device 10 according to the first embodiment, it is possible to calculate the temperature with high accuracy by using the detection wavelengths λ ₂ and λ ₃ whose transmittance can be reduced due to the presence of the absorber such as water vapor. For example, the outside of the range of the atmospheric window, which has been conventionally unsuitable, can be used as the detection wavelength. That is, even when the detection wavelengths λ ₂ and λ ₃ belong to ₃ to 3.5 μm, 4.5 to 8 μm or 13 to 16 μm, the temperature and the transmittance can be calculated with high accuracy.

Since the absorber ABS existing between the object 20 and the infrared detection device 10 is determined by the wavelengths λ ₂ and λ ₃ , the type of the absorber ABS is inspected in advance especially in the atmosphere. No need.
(Effects on gas sensor)
The effect of using the infrared detection device 10 according to the first embodiment as a gas sensor will be described.

The infrared detection device 10 according to the first embodiment can calculate the transmittance of the absorber ABS and at the same time calculate the absolute amount of the absorber ABS. When the distance between the object 20 and the infrared detection device 10 is known, the concentration of the absorber can be calculated. For example, if the absorber is water vapor, the amount of water vapor and the humidity at the distance between the object 20 and the infrared detection device 10 can be calculated. The target absorber ABS is not limited to water vapor, but may be a gas absorber such as carbon dioxide or a scatterer such as an aerosol.

With the infrared detection device 10 according to the first embodiment, the concentration of the absorber can be calculated with high accuracy as long as the temperature of the target object 20 is within a certain range. That is, for example, in comparison with the gas sensor using the infrared detector represented by Patent Document 3, the infrared detecting device 10 according to the first embodiment does not require a light source as a constituent element. Therefore, in a situation where it is difficult to install a light source or a situation where energy consumption is desired to be suppressed, calculation of gas concentration using the infrared detection device 10 according to the first embodiment is very effective. That is, since the infrared detection device 10 can be used as a space-saving and energy-saving gas sensor, it can be used as an IoT device in which a large number of sensors need to be arranged.

Since the absorber existing between the object 20 and the infrared detection device 10 is determined by the wavelengths λ ₂ and λ ₃ , it is not necessary to inspect the type of the absorber in advance especially in the atmosphere. Absent.

The distance between the object 20 and the infrared detection device 10 may be measured in advance if the object 20 and the infrared detection device 10 are fixed. When the infrared detection device 10 includes a lens, the focal length of the lens may be the distance between the object 20 and the infrared detection device 10.
(Effects of radiation thermometer and gas sensor)
The effect when the infrared detection device 10 according to the first embodiment is used as a detection device having both functions of a radiation thermometer and a gas sensor will be described.

Which gas species the infrared detection device 10 according to the first embodiment detects depends on whether or not it has absorption at the detection wavelength. For example, with water vapor, the humidity can be calculated while measuring the temperature of the object 20 regardless of whether it is indoors or outdoors. In Patent Document 2, a hygrometer is provided, but this hygrometer measures the humidity in the vicinity of the radiation thermometer.

On the other hand, the infrared detection device 10 according to the first embodiment measures the average humidity from the object 20 to the detectors 2 and 3. Therefore, in a situation where the environment between the object 20 and the detectors 2 and 3 is significantly different, the calculation of temperature and humidity using the infrared detection device 10 according to the first embodiment is very effective. That is, since the infrared detection device 10 according to the first embodiment can be used to detect the temperature and the amount of water vapor in a cooking utensil in which water vapor is retained, the user or the cooking utensil itself determines the cooking state and provides feedback. can do.

For example, if the gas type to be detected is carbon dioxide, the carbon dioxide concentration can be calculated while measuring the temperature of the object regardless of whether it is indoors or outdoors. Patent Document 4 is a gas sensor that detects the carbon dioxide concentration, and this gas sensor measures the carbon dioxide concentration near the installation location.

On the other hand, the infrared detection device 10 according to the first embodiment measures the average carbon dioxide concentration from the object 20 to the detectors 2 and 3. Therefore, in a situation where the environment between the object 20 and the detectors 2 and 3 is greatly different, the calculation of the temperature and the carbon dioxide concentration using the infrared detection device 10 according to the first embodiment is very effective. That is, in the ventilation equipment and the air conditioning equipment for adjusting the carbon dioxide concentration, the infrared detection device 10 according to the first embodiment can be used for detecting the indoor/outdoor carbon dioxide concentration and so on. The air conditioner itself can determine the state of carbon dioxide concentration and feed it back.

If the target to be detected is not an absorber such as gas but a scatterer such as aerosol, the concentration of the scatterer can be calculated while measuring the temperature of the target. That is, in the ventilation equipment, the air conditioning equipment, and the air cleaner, since the infrared detection device 10 according to the first embodiment can be used for detecting scatterers, the user or the ventilation equipment, the air conditioning equipment, and the air cleaner itself. Can judge the state of the concentration of the scatterer and feed it back.
(Effects of radiation thermometer and gas sensor for measuring substantial temperature)
In the following, the substantial temperature around the object 20 is simply referred to as “substantial temperature”.

Since the infrared detection device 10 according to the first embodiment can detect the temperature and the concentration of the absorber at the same time, it can be used as a device for measuring the substantial temperature calculated from the temperature of the object 20 and the concentration of the absorber and the index of comfort. It is suitable. For example, by detecting the temperature and the humidity at the same time, the substantial temperature calculated from the temperature and the humidity can be measured. The substantial temperature includes, for example, a sensible temperature, which is a temperature felt by a person, and an effective heating temperature applied to food by a cooking device. Generally, as the temperature and humidity of the object 20 increase, the substantial temperature increases.

A suitable wavelength for calculating the substantial temperature will be described. As described above, in the first embodiment, when the temperature of the target object 20 changes, the ratio of the black body spectral radiance changes slightly, so that a calculation error occurs in the temperature and the transmittance of the target object 20. That is, the accuracy of calculating the temperature and the transmittance of the object 20 depends on the accuracy of dividing the ratio of the black body spectral radiance and the ratio of the transmittance.

On the other hand, even if the difference between the temperature of the object 20 and the transmittance is accompanied by an error, the substantial temperature can be calculated with high accuracy. For example, regardless of whether the value of temperature or humidity is increased, under the condition that the ratio of the spectral irradiance increases, the calculation error due to the carving can be canceled out, so that the actual temperature must be calculated with high accuracy. You can In other words, due to experimental error and deviation from the transmission model, the temperature and humidity are not sufficiently separated, and even if the humidity is calculated higher (lower) than it actually is, the temperature is calculated lower (higher), so When converted to, the calculation error becomes smaller. In other words, the substantial temperature can be calculated with high accuracy by selecting the wavelength so that the correlation between the substantial temperature and the ratio of the spectral irradiance becomes large.

When the detection wavelengths λ ₂ and λ ₃ are set to λ ₂ <λ ₃ according to the first embodiment, when the temperature of the target object 20 increases, the blackbody spectroscopy of the detection wavelengths λ ₂ and λ ₃ is caused by the property of Planck's equation. The irradiance ratio (B(λ ₂ , T)/B(λ ₃ , T)) increases. In other words, as the temperature of the object 20 increases, the ratio of the spectral irradiances of the detector 2 and the detector 3 (I(λ ₂ , T)/I(λ ₃ , T)) increases.

Therefore, if the wavelengths λ ₂ and λ _{3 in} which the transmittance ratio (τ(λ ₂ )/τ(λ ₃ )) increases with an increase in humidity are selected, the spectral radiation of the detector 2 and the detector 3 will be increased. The illuminance ratio (I(λ ₂ , T)/I(λ ₃ , T)) also increases, and the substantial temperature calculation error due to the temperature/humidity separation error is reduced.

FIG. 10 is a diagram showing the relationship between the transmittance of water vapor and the wavelength. In FIG. 10, the vertical axis represents the water vapor transmission rate at a certain humidity, and the horizontal axis represents the wavelength.

Here, a schematic diagram of the relationship between the transmittance of water vapor and the wavelength at a certain humidity is shown in FIG. In the wavelength region of 3.0 to 16 μm, the water vapor transmission rate can be classified into three types: a high transmission rate region, a first low transmission rate region, and a second low transmission rate region. The high transmittance region is a wavelength region showing a high transmittance of 3.5 to 4.5 μm and 8.0 to 13.0 μm. The first low transmittance region is a low transmittance region of 3.0 to 3.5 μm and 6.0 to 8.0 μm and a wavelength region where the transmittance increases as the wavelength becomes longer. The second low transmittance region is a low transmittance region of 4.5 to 6.0 μm and 13.0 to 16.0 μm and a wavelength region where the transmittance decreases as the wavelength becomes longer.

According to the Lambert-Beer law shown in the equation (4), there is a negative correlation between the transmittance and the extinction coefficient at the same absorber concentration. That is, the wavelength condition in which the transmittance ratio (τ(λ ₂ )/τ(λ ₃ )) increases with an increase in humidity satisfies τ(λ ₂ )>τ(λ ₃ ) in FIG. Wavelength. That is, when the detection wavelength λ ₂ belongs to the high transmittance region and the detection wavelength λ ₃ belongs to the adjacent low transmittance region (that is, the second low transmittance region), and the detection wavelengths λ ₂ and λ ₃ Belong to the same second low transmittance region.

That is, when the detection wavelength λ ₂ belongs to the range of 3.5 to 4.5 μm and the detection wavelength λ ₃ belongs to the range of 4.5 to 6.0 μm, the substantial temperature can be calculated with high accuracy. it can. Alternatively, when the detection wavelength λ ₂ belongs to the range of 8.0 to 13.0 μm and the detection wavelength λ ₃ belongs to the range of 13.0 to 16.0 μm, the substantial temperature can be calculated with high accuracy. .. Alternatively, when the detection wavelengths λ ₂ and λ ₃ belong to the range of 4.5 to 6.0 μm, the substantial temperature can be calculated with high accuracy. Alternatively, when the detection wavelengths λ ₂ and λ ₃ belong to the range of 13.0 to 16.0 μm, the substantial temperature can be calculated with high accuracy.

Regarding the calculation of the actual temperature, the calculation unit for calculating the actual temperature directly from the spectral irradiance of the detection wavelengths λ ₂ and λ ₃ is used instead of the brightness ratio parameter 43 and the transmittance calculation table 42. 4 may be arranged.
(Effects of radiation thermometer and gas sensor for measuring comfort index)
The comfort index may be calculated based on not only the actual temperature but also the temperature and the carbon dioxide concentration or the temperature and the aerosol concentration. As a result, the user, the cooker, the ventilation device, the air conditioner, and the air purifier can perform feed back by making judgments based on the substantial temperature and the index of comfort.

With respect to the comfort index that decreases when the temperature and the carbon dioxide concentration increase, a suitable wavelength will be described. Similar to the case of the substantial temperature, the condition that can reduce the error in separating the temperature of the object 20 and the transmittance is that the ratio of the transmittance (τ(λ ₂ )/τ( with respect to the increase of the carbon dioxide concentration). There are two detection wavelengths that increase λ ₃ )).

FIG. 11 is a diagram showing the relationship between the carbon dioxide transmittance at a certain humidity and the wavelength. In FIG. 11, the vertical axis represents the carbon dioxide transmittance at a certain humidity, and the horizontal axis represents the wavelength.

Here, a schematic diagram of the relationship between the carbon dioxide transmittance and the wavelength at a certain humidity is shown in FIG. 11. In the case of carbon dioxide transmittance, the wavelength range of 3.0 to 16 μm can be classified into three types: a high transmittance area, a second low transmittance area, and a third low transmittance area. The high transmittance region is a wavelength region showing a high transmittance of 3.5 to 4.0 μm and 4.5 to 13.5 μm. The second low transmittance region is a low transmittance region of 13.5-16.0 μm and a wavelength region in which the transmittance decreases as the wavelength becomes longer. The third low transmittance region is a wavelength region showing a low transmittance of 4.0 to 4.5 μm.

According to the Lambert-Beer law shown in the equation (4), there is a negative correlation between the transmittance and the extinction coefficient at the same absorber concentration. That is, the wavelength condition in which the transmittance ratio (τ(λ ₂ )/τ(λ ₃ )) increases with increasing humidity satisfies τ(λ ₂ )>τ(λ ₃ ) in FIG. 11. Wavelength. That is, when the detection wavelength λ ₂ belongs to the high transmittance region and the detection wavelength λ ₃ belongs to the adjacent low transmittance region (that is, the second low transmittance region), and the detection wavelengths λ ₂ and λ ₃ Belong to the same second low transmittance region.

That is, when the detection wavelength λ ₂ is in the range of 3.5 to 4.0 μm and the detection wavelength λ ₃ is in the range of 4.0 to 4.5 μm, the comfort index can be calculated with high accuracy. it can. Alternatively, when the detection wavelength λ ₂ belongs to the range of 4.5 to 13.5 μm and the detection wavelength λ ₃ belongs to the range of 13.5 to 16.0 μm, the comfort index can be calculated with high accuracy. .. Alternatively, when the detection wavelengths λ ₂ and λ ₃ belong to the range of 13.5 to 16.0 μm, the comfort index can be calculated with high accuracy.

Regarding the calculation of the comfort index, the calculation parameter for directly calculating the comfort index from the spectral irradiance of the detection wavelengths λ ₂ and λ ₃ is used instead of the brightness ratio parameter 43 and the transmittance calculation table 42. It may be arranged at 4A.
(Effects of Application of First Embodiment)
In the first embodiment, the emissivity needs to be known. This is because it is known that the target object 20 is a person, an animal, a cooking utensil, a cooking utensil material, or the like. Good.

By forming the infrared detection device 10 according to the first embodiment into an array, it can be used as an infrared camera. An infrared camera to which the infrared detection device 10 is applied can simultaneously capture both an image regarding the temperature of the object 20 and an image regarding the absolute amount of the absorber. With this function, the contour and distribution of the object 20 can be determined with higher accuracy.

[Embodiment 2]
FIG. 12 is a schematic diagram of an infrared detection device according to the second embodiment. With reference to FIG. 12, an infrared detection device 10A according to the second embodiment is a device in which the calculation unit 4 of the infrared detection device 10 shown in FIG. 1 is replaced with a calculation unit 4A and a detector 1 is added. It is the same as the detection device 10.

The detector 1 detects the spectral irradiance I(λ ₁ , T) of the infrared IFR 1 having the wavelength λ ₁ (<λ ₂ ) and sends the detected spectral irradiance I(λ ₁ , T) to the calculation unit 4A. Output. The wavelength λ ₁ may be longer or shorter than the above-mentioned peak wavelength λ _max .

Two or three of the detectors 1 to 3 may be the same or different from each other. When the detectors 1 to 3 or two detectors of the detectors 1 to 3 are the same, that is, when the detectors 1 to 3 are composed of one or two detectors, the detectors 1 to 1 The detectors responsible for multiple detections of 3 are quantum dot detectors or quantum well detectors. The quantum dot detector or the quantum well detector can control the detection wavelength according to the applied voltage. As a result, only one detector is required, so that the infrared detector 10A can be downsized and the cost can be reduced. When the detectors 1 to 3 are configured by one or two detectors, the infrared detection device 10A controls the voltage applied to the detector (comprising a quantum dot type detector or a quantum well type detector), The control part which controls the wavelength to detect is further provided. When the detectors 1 to 3 are configured by one detector, the control unit controls the voltage V ₁ for setting the wavelength to be detected at the wavelength λ ₁ and the voltage V ₁ for setting the wavelength to be detected at the wavelength λ _2. has a V _2, the voltage V ₃ for setting the wavelength for detecting the wavelength lambda _3, the two functions of the three functions of controlling the.

The calculation unit 4A is obtained by adding a transmittance calculation table 45 to the calculation unit 4 shown in FIG. Transmittance calculation table 45, the wavelength lambda _2, the wavelength lambda _3, and the wavelength lambda _2, any of the transmittance of both _{λ 3 (τ (λ 1)} , τ (λ 2) and τ (λ _1), τ It is a table for calculating the transmittance τ(λ ₁ ) from (any one of λ ₂ ).

In the second embodiment, as in the first embodiment, two wavelengths λ ₂ and λ ₃ are selected based on the accuracy rating of the radiation thermometer and the measurement range of the temperature of the object 20, and the black body spectroscopy is selected. It is used that the temperature dependence of the ratio of the radiance B(λ ₂ , T) and the black body spectral radiance B(λ ₃ , T) is small. That is, the approximate value R _est of the ratio of the black body spectral radiance B(λ ₂ , T) and the black body spectral radiance B(λ ₃ , T) is used. Further, in the second embodiment, emissivity ε(λ ₁ ), ε(λ ₂ ), ε(λ ₃ ) and extinction coefficients ε _a (λ ₁ ), ε _a (λ ₂ ), ε _a (λ ₃ ). ) Shall be known.

The calculating unit 4A receives the spectral irradiances I(λ ₁ , T) to I(λ ₃ , T) from the detectors 1 to 3, respectively. The calculation unit 4A also detects the approximate value R _est from the brightness ratio parameter 43. Then, the calculating unit 4A approximates the ratio of the spectral irradiance I(λ ₂ , T), I(λ ₃ , T), the emissivity ε(λ ₂ ), ε(λ ₃ ) and the black body spectral radiance. Substituting R _est into the equation (10), the transmittance ratio τ(λ ₂ )/τ(λ ₃ ) is calculated. In this case, the calculation unit 4A substitutes the approximate value R _est into R of the equation (10).

Then, calculating unit 4B is calculated transmittance ratio τ (λ ₂₎ / τ is calculated transmittance tau a (lambda ₂₎ on the basis of (λ _3). More specifically, the calculation unit 4A is calculated ratio of the transmittance _{τ (λ 2) / τ (} λ 3) to apply the formula (5) is calculated transmittance tau a (lambda _2). Further, the calculation unit 4A detects the transmittance τ(λ ₂ ) corresponding to the calculated transmittance ratio τ(λ ₂ )/τ(λ ₃ ) by using the transmittance calculation table 42, and thereby the transmittance τ(λ ₂ ). The transmittance τ(λ ₂ ) is calculated from the ratio τ(λ ₂ )/τ(λ ₃ ).

When the Lambert-Beer law holds for the wavelengths λ ₁ and λ ₂ , the following equation holds between the transmittance τ(λ ₁ ) and the transmittance τ(λ ₂ ).

従って、算出部４Ａは、透過率τ（λ_２）を算出すると、その算出した透過率τ（λ_２）に基づいて透過率τ（λ_１）を算出する。より具体的には、算出部４Ａは、算出した透過率τ（λ_２）と、吸光係数ε_ａ（λ_１），ε_ａ（λ_２）とを式（２２）に代入して透過率τ（λ_１）を算出する。また、算出部４Ａは、透過率算出テーブル４５を用いて、算出した透過率τ（λ_２）に対応する透過率τ（λ_１）を検出することによって透過率τ（λ_２）から透過率τ（λ_１）を算出する。

Therefore, when calculating the transmittance τ(λ ₂ ), the calculation unit 4A calculates the transmittance τ(λ ₁ ) based on the calculated transmittance τ(λ ₂ ). More specifically, the calculation unit 4A substitutes the calculated transmittance τ(λ ₂ ) and the extinction coefficients ε _a (λ ₁ ), ε _a (λ ₂ ) into the equation (22), and the transmittance τ. Calculate (λ ₁ ). Further, the calculation unit 4A uses the transmittance calculation table 45 to detect the transmittance τ(λ ₁ ) corresponding to the calculated transmittance τ(λ ₂ ), and thereby the transmittance τ(λ ₂ ) to the transmittance τ(λ ₂ ). Calculate τ(λ ₁ ).

Then, the calculation unit 4A causes the spectral irradiances I(λ ₁ , T), I(λ ₂ , T), the transmittances τ(λ ₁ ), τ(λ ₂ ) and the emissivities ε(λ ₁ ), ε(. λ ₂ ) is substituted into equation (3) to calculate the black body spectral radiance ratio B(λ ₂ , T)/B(λ ₁ , T).

When the temperature of the object 20 is calculated by the two-color method, the black body spectral radiance ratio B(λ ₁ , T)/B(λ ₂ , T) is expressed by the following equation.

従って、算出部４Ａは、黒体分光放射輝度の比Ｂ（λ_２，Ｔ）／Ｂ（λ_１，Ｔ）を算出すると、その算出した黒体分光放射輝度の比Ｂ（λ_２，Ｔ）／Ｂ（λ_１，Ｔ）を式（２３）に代入して対象物２０の温度Ｔを算出する。

Therefore, when the calculation unit 4A calculates the black body spectral radiance ratio B(λ ₂ , T)/B(λ ₁ , T), the calculated black body spectral radiance ratio B(λ ₂ , T). Substituting /B(λ ₁ , T) into the equation (23), the temperature T of the object 20 is calculated.

FIG. 13 is a flowchart for explaining the detection method according to the second embodiment for detecting the temperature of the object 20 and/or the absolute amount or concentration of the absorber.

The flowchart shown in FIG. 13 is obtained by replacing steps S1, S5, and S6 of the flowchart shown in FIG. 3 with steps S1A, S5A, and S6A, respectively, and replacing step S7 with steps S8 and S9. It is the same as the flowchart.

With reference to FIG. 13, when the operation of detecting the temperature of the target object 20 and/or the absolute amount or concentration of the absorber is started, the detectors 1 to 3 respectively detect the spectral irradiance I(λ ₁ , T). ), I(λ ₂ , T), I(λ ₃ , T) are detected (step S1A), and the detected spectral irradiances I(λ ₁ , T), I(λ ₂ , T), I(λ ₃ ,T) is output to the calculation unit 4A.

Then, step S2 to step S4 described above are sequentially executed. Then, after step S4, the calculation unit 4A calculates the transmittance τ(λ ₁ ) based on the calculated transmittance τ(λ ₂ ) (step S5A). More specifically, the calculation unit 4A substitutes the calculated transmittance τ(λ ₂ ) and the extinction coefficients ε _a (λ ₁ ), ε _a (λ ₂ ) into the equation (22), and the transmittance τ. Calculate (λ ₁ ). Further, the calculation unit 4A uses the transmittance calculation table 45 to detect the transmittance τ(λ ₁ ) corresponding to the calculated transmittance τ(λ ₂ ), and thereby the transmittance τ(λ ₂ ) to the transmittance τ(λ ₂ ). Calculate τ(λ ₁ ).

After step S5A, the calculation unit 4A causes the spectral irradiances I(λ ₁ , T), I(λ ₂ , T), the transmittances τ(λ ₁ ), τ(λ ₂ ) and the emissivity ε(λ ₁ ). , Ε(λ ₂ ) into equation (3) to calculate the black body spectral radiance ratio I(λ ₂ , T)/I(λ ₁ , T) (step S6A).

Subsequently, the calculation unit 4A calculates the temperature of the object 20 by substituting the calculated black body spectral radiance ratio I(λ ₂ , T)/I(λ ₁ , T) into the equation (23) ( Step S8). Then, the calculation unit 4A calculates the absolute amount or concentration of the absorber ABS based on the transmittance τ(λ ₁ ) or the transmittance τ(λ ₂ ) (step S9). This ends the operation of detecting the temperature of the object 20 and/or the absolute amount or concentration of the absorber.

In the second embodiment, the operation of detecting the temperature of the object 20 and/or the absolute amount or concentration of the absorber ABS may be executed by software. In this case, the calculation unit 4A includes a CPU, ROM and RAM.

The ROM receives step S1-1A that receives the spectral irradiance I(λ ₁ , T), the spectral irradiance I(λ ₂ , T), and the spectral irradiance I(λ ₃ , T) from the detectors 1 to 3, respectively. Emissivity ε(λ ₁ ), ε(λ ₂ ), ε(λ ₃ ) and extinction coefficients ε _a (λ ₁ ), ε _a (λ ₂ ), ε _a (λ ₃ ) via an input device (keyboard or the like). ) Is received, and a program Prog_E including steps S2 to S4, S5A, S6A, S8, and S9 shown in FIG. 13 is stored. The ROM also stores the transmittance calculation table 42, the brightness ratio parameter 43, and the transmittance calculation table 45 shown in FIG. The RAM has the spectral irradiances I(λ ₁ , T), I(λ ₂ , T), I(λ ₃ , T), emissivity ε(λ ₁ ), ε(λ ₂ ), ε received by the CPU. (Λ ₃ ) and extinction coefficient ε _a (λ ₁ ), ε _a (λ ₂ ), ε _a (λ ₃ ), an approximate value R _est of the ratio of the black body spectral radiance detected by the CPU, calculated by the CPU Based on the transmittance ratio τ(λ ₂ )/τ(λ ₃ ), the transmittance ratio τ(λ ₂ )/τ(λ ₃ ), and the extinction coefficient ε _a (λ ₂ ), ε _a (λ ₃ ). Ratio B of the transmittance τ(λ ₂ ) calculated by the CPU, the transmittance τ(λ ₁ ) calculated by the CPU based on the transmittance τ(λ ₂ ) and the black body spectral radiance calculated by the CPU (Λ ₂ , T)/B(λ ₁ , T) and the temperature T of the object 20 calculated by the CPU are temporarily stored.

The CPU reads the program Prog_E from the ROM, sequentially executes steps S1-1A, S1-2A, S2 to S4, S5A, S6A, S8, and S9 of the read program Prog_E, and executes the object 20 by the method described above. Temperature and/or the absolute amount or concentration of absorber ABS.

In this case, the CPU that detects the approximate value R _est of the black body spectral radiance ratio constitutes a “detection unit”, and the transmittance ratio τ(λ ₂ )/τ(λ ₃ ), the transmittance τ(λ ₂ ), τ(λ ₁ ) and the CPU that calculates the temperature T constitute “calculation means”. Further, spectral irradiances I(λ ₁ , T), I(λ ₂ , T), I(λ ₃ , T), emissivity ε(λ ₁ ), ε(λ ₂ ), ε(λ ₃ ) and absorption The CPU that receives the coefficients ε _a (λ ₁ ), ε _a (λ ₂ ), and ε _a (λ ₃ ) constitutes “reception means”.

Further, the program Prog_E may be recorded in a recording medium (for example, CD and DVD) and distributed. In this case, the computer (CPU) reads the program Prog_E from the recording medium and executes it to detect the temperature of the object 20 and/or the absolute amount or concentration of the absorber ABS. Therefore, a CD, a DVD, or the like in which the program Prog_E is recorded is a computer (CPU) readable recording medium in which the program Prog_E is recorded.

Further, in the second embodiment, the calculation unit 4A may calculate the temperature of the target object 20 according to the flowchart shown in FIG. In this case, the calculation unit 4A may calculate the calculated temperature T _est1 of the target object 20 according to steps S1, S2, and S31 of FIG. 6, and use the calculated calculated temperature T _est1 as the temperature of the target object 20. step S1 of, S2, S31, and calculates the calculated temperature _{T est2} of object 20 according to S32, or the calculated temperature _{T est2} that the calculated as the temperature of the object 20.

[Temperature calculation accuracy]
The effect in the second embodiment will be described by taking the infrared detection device in which the target object 20 is in the temperature range of 0 to 100° C. and the temperature is calculated by correcting the transmittance of water vapor.
(Setting of infrared detector)
First, the infrared detection device 10A is prepared in advance according to the second embodiment. Hereinafter, specific examples in the case where the absorber is water vapor will be shown. For simplicity, the same detection conditions as in Embodiment 1 are assumed. Further, the detection rate α is 0.1 and the emissivity ε(λ ₁ ), ε(λ ₂ ), ε(λ ₃ ) is 1.

The detection wavelength λ _{1 is selected} to be 8.5 μm, the detection wavelength λ ₂ is set to 13.0 μm, and the detection wavelength λ _{3 is set} to 13.5 μm from the range of the window of the atmosphere shown in FIG. 7.

The brightness ratio parameter 43 and the transmittance calculation tables 42 and 45 are set in the calculator 4A. Further, the value of the brightness ratio parameter 43 is set to 0.947. For example, since the ratio of the black body spectral radiance when the temperature of the black body is 0 to 100° C. is 0.930 to 0.965, the ratio of the black body spectral radiance changes by about 3.6%.

The transmittance calculation table 42 uses the formula (5) for calculating the transmittance from the transmittance ratio to calculate the extinction coefficient ratio ε _a (λ ₂ )/ε _a (λ ₃ ), for example, referring to FIG. 7. And create it as 0.5. This is the ratio of the extinction coefficients of water vapor at wavelengths of 13.0 μm and 13.5 μm.

The transmittance calculation table 45 is based on the equation (22) for calculating the transmittance τ(λ ₁ ) from the transmittance τ(λ ₂ ), and the extinction coefficient ratio ε _a (λ ₁ )/ε _a (λ ₂ ) Is created as 0.37 with reference to FIG. 7, for example. This is the ratio of the extinction coefficient of water vapor at a wavelength of 8.5 μm and a wavelength of 13.0 μm.
(Calculation accuracy according to the second embodiment)
The calculation accuracy of the temperature in the second embodiment will be described based on the simulation. First, we created a simulation task. Set the transmittances τ(λ ₁ )=0.50, τ(λ ₂ )=0.25 and τ(λ ₃ )=0.77 to match the adopted extinction coefficient ratios of 0.5 and 0.37. Then, the spectral irradiances I (8.5 μm, T), I (13 μm, T), and I (13.5 μm, T) corresponding to each temperature were calculated based on the equation (1). This spectral irradiance is defined as the spectral irradiances I(λ ₁ , T), I(λ ₂ , T), I(λ ₃ , T) detected by the detectors 1 to ₃ , and based on the second embodiment. Then, the temperature of the object 20 was calculated.

First, from the approximate value R _est of the ratio of the spectral irradiance I (13 μm, T), I (13.5 μm, T) of the spectral irradiance and the ratio of the blackbody spectral radiance set in the brightness ratio parameter 43, The ratio of the rates was calculated based on equation (10). Then, from the ratio of the ratio of transmittance and extinction coefficient, based from equation (5) transmission based on tau (lambda ₂₎ to calculate the transmittance was the calculated tau (lambda ₂₎ in equation (22) The transmittance τ(λ ₁ ) was calculated. Then, from the spectral irradiances I (13 μm, T), I (13.5 μm, T) and the transmittances τ(λ ₁ ), τ(λ ₂ ), the black body spectral radiance ratio B is calculated based on the equation (3). (Λ ₂ , T)/B(λ ₁ , T) is calculated, and the calculated ratio B(λ ₂ , T)/B(λ ₁ , T) of the blackbody spectral radiance is substituted into equation (23). Then, the temperature of the object 20 was calculated.

FIG. 14 is a diagram showing a temperature difference between the set temperature of the target object 20 and the calculated temperature obtained by the simulation. In FIG. 14, the vertical axis represents the difference between the calculated temperature and the temperature of the target object 20, and the horizontal axis represents the temperature of the target object 20.

With reference to FIG. 14, even when the transmittance depends on the wavelength, the calculated temperature falls within an error of about −2.9° C. to +1.5° C. with respect to the temperature of the object 20. That is, assuming that the detection wavelength λ ₂ is 13.0 μm, the detection wavelength λ ₃ is 13.5 μm, and the ratio of the black body spectral radiance at these wavelengths is 0.947, the target object 20 has a temperature of 0 to 100° C. Within the temperature range, the temperature can be calculated with the accuracy of −2.9° C. to +1.5° C. by the method in the second embodiment.

[Effects of Second Embodiment]
The effect of the second embodiment will be described.
(Effects of radiation thermometer)
The effect of using the infrared detection device 10A according to the second embodiment as a radiation thermometer will be described.

In the conventional monochromatic method, the temperature is calculated by setting the transmittance to a value that is predicted in advance. Therefore, if the transmittance differs from the value, a calculation error occurs in the temperature. For example, assume that a monochromatic radiation thermometer (infrared ray detection device 10A) that detects a detection wavelength of 8.5 μm is used, and the transmittance should be set to 0.77 when it should be set to 0.77. That is, the radiation thermometer (infrared detector 10A) estimates the spectral radiance of the object 20 to be 0.77 times the original value. Under this condition, when the temperature of the target object 20 of 35° C. is detected according to the equation (1), the calculated temperature becomes about 21° C., which causes a large error.

Further, in the conventional two-color method, since the transmittance has wavelength dependency, it is not possible to calculate temperature with high accuracy. In the conventional two-color method, the temperature is calculated on the assumption that the transmittance does not depend on the wavelength. Therefore, when the actual transmittance has the wavelength dependency, a calculation error occurs in the temperature. For example, using a conventional two-color radiation thermometer that detects infrared rays having a detection wavelength of 8.5 μm and infrared rays having a detection wavelength of 13.0 μm, the transmittance is τ(8.5 μm)=0.77 and τ( It is assumed that the temperature of the object 20 is calculated under the condition of 13.0)=0.5. Under this condition, if the temperature is calculated by regarding the ratio of the spectral irradiance as the ratio of Planck's equation, the temperature 35° C. of the object 20 is calculated as the temperature 137° C.

On the other hand, as shown in the simulation and FIG. 14, the infrared detection device 10A according to the second embodiment can calculate an accurate temperature even when the transmittance depends on the wavelength. That is, the infrared detection device 10A according to the second embodiment has a transmittance correction function that is not found in conventional radiation thermometers.

According to the second embodiment, by adding the detector 1 to the first embodiment, it is possible to calculate the temperature using the two-color method. That is, unlike the first embodiment in which it is necessary to know the emissivity of the object 20 in advance, the second embodiment can accurately measure the temperature if the emissivity of the object 20 does not depend on the wavelength. It can be calculated. For example, the temperature of the target object 20 is not limited to a person, an animal, a cooking utensil, a cooking tool material, or the like, and the temperature of the general outdoor target object 20, such as a person, a car, a road surface, or a tree, is calculated with high accuracy. be able to.

Further, in the second embodiment, the transmittance and the temperature can be calculated with high accuracy without being affected by the apparent emissivity due to the angle between the object 20 and the infrared detection device 10A. In other words, the infrared detection device 10A according to the second embodiment does not necessarily need to be arranged at right angles to the object 20. Therefore, the user can arbitrarily arrange the infrared detection device 10A and calculate the transmittance and the temperature. For example, by disposing the infrared detection device 10A at the corner of the room, it is possible to monitor the transmittance and the temperature of the entire room.

Further, according to the second embodiment, as in the case of the first embodiment, it is possible to calculate the temperature with the transmittance corrected. Thereby, for example, in an environment where the transmittance greatly changes due to the influence of water vapor (for example, outdoors in bad weather such as rain or fog, a bathroom, etc.), it is possible to improve the detection performance of humans or animals. That is, in bad weather, it is possible to detect a person or an animal from a farther distance, and it is possible to detect an accident in a bathroom early.

Further, according to the infrared detection device 10A according to the _second embodiment, the temperature is calculated with high accuracy by using the detection wavelengths λ ₁ , λ ₂ , and λ ₃ whose transmittance can be reduced due to the presence of an absorber such as water vapor. be able to. For example, the outside of the range of the atmospheric window, which has been conventionally unsuitable, can be used as the detection wavelength. That is, even when the detection wavelengths λ ₁ , λ ₂ , and λ ₃ belong to ₃ to 3.5 μm, 4.5 to 8 μm, or 13 to 16 μm, the temperature and the transmittance can be calculated with high accuracy. In particular, the infrared detection device 10A according to the second embodiment uses the outside of the window of the atmosphere as the detection wavelength λ ₁ or the detection wavelength λ ₃ to increase the difference in wavelength used for calculating the ratio of the spectral radiance. Can be taken. As a result, the change in the ratio of the spectral radiance when the temperature of the object 20 changes can be further increased, and the temperature can be calculated with higher accuracy as compared with the existing two-color thermometer.

The absorber ABS existing between the object 20 and the infrared detection device 10A is determined by the wavelengths λ ₁ and λ _2. Therefore, especially in the atmosphere, the type of the absorber ABS is inspected in advance. No need.
(Effects on gas sensor)
The effect of using the infrared detection device 10A according to the second embodiment as a gas sensor will be described.

The infrared detection device 10A according to the second embodiment can calculate the transmittance of the absorber and the absolute amount of the absorber at the same time. When the distance between the object 20 and the infrared detection device 10A is known, the concentration of the absorber can be calculated. For example, if the absorber is water vapor, the amount of water vapor and the humidity at the distance between the object 20 and the infrared detection device 10A can be calculated. The target absorber is not limited to water vapor, but may be a gas absorber such as carbon dioxide or a scatterer such as an aerosol.

According to the infrared detection device 10A according to the second embodiment, the concentration of the absorber can be calculated with high accuracy as long as the temperature of the target object 20 is within a certain range. That is, for example, as compared with a gas sensor using an infrared detector typified by Patent Document 3, the infrared detection device 10A according to the second embodiment does not require a light source as a constituent element. Therefore, in a situation where it is difficult to install a light source or a situation where energy consumption is desired to be suppressed, calculation of the gas concentration in the infrared detection device 10A according to the second embodiment is very effective. That is, since the infrared detection device 10A can be used as a space-saving and energy-saving gas sensor, it can be used as an IoT device in which a large number of sensors need to be arranged.

Since the absorber ABS existing between the object 20 and the infrared detection device 10A is determined by the wavelengths λ ₂ and λ ₃ , especially in the atmosphere, the type of the absorber ABS is inspected in advance. No need.

The distance between the target object 20 and the infrared detection device 10A may be measured in advance if the target object 20 and the infrared detection device 10A are fixed. When the infrared detection device 10A is provided with a lens, the focal length of the lens may be the distance between the object 20 and the infrared detection device 10A.
(Effects of radiation thermometer and gas sensor)
The effect when the infrared detection device 10A according to the second embodiment is used as a detection device having both functions of a radiation thermometer and a gas sensor will be described.

Which gas species the infrared detection device 10A according to the second embodiment detects depends on whether or not the detection wavelength has absorption. For example, with water vapor, the humidity can be calculated while measuring the temperature of the object 20 regardless of whether it is indoors or outdoors. In Patent Document 2, a hygrometer is provided, but this hygrometer measures the humidity in the vicinity of the radiation thermometer.

On the other hand, the infrared detection device 10A according to the second embodiment measures the average humidity from the object 20 to the detectors 1 to 3. Therefore, in a situation where the environment between the object 20 and the detectors 1 to 3 is greatly different, the temperature and humidity calculation by the infrared detection device 10A is very effective. That is, since the cooking utensil containing steam can be used for detecting the temperature and the amount of water vapor, the user or the cooking utensil itself can judge the cooking state and feed it back.

For example, if the gas type to be detected is carbon dioxide, the carbon dioxide concentration can be calculated while measuring the temperature of the object regardless of whether it is indoors or outdoors. Patent Document 4 is a gas sensor that detects the carbon dioxide concentration, and this gas sensor measures the carbon dioxide concentration near the installation location.

On the other hand, the infrared detection device 10A according to the second embodiment measures the average carbon dioxide concentration from the object 20 to the detectors 1 to 3. Therefore, in a situation where the environment between the object 20 and the detectors 1 to 3 is greatly different, the calculation of the temperature and the carbon dioxide concentration in the infrared detection device 10A according to the second embodiment is very effective. In other words, in the ventilation equipment and air conditioning equipment that adjust the carbon dioxide concentration, it can be used to detect the indoor and outdoor carbon dioxide concentration. You can judge and give feedback.

If the target to be detected is not an absorber such as gas but a scatterer such as aerosol, the concentration of the scatterer can be calculated while measuring the temperature of the target. That is, since it can be used for detecting scatterers in ventilation equipment, air conditioning equipment and air cleaners, the user or the ventilation equipment, air conditioning equipment and air cleaner itself can judge the state of scatterer concentration. , You can give feedback.
(Effects of radiation thermometer and gas sensor for measuring actual temperature)
Since the infrared detection device 10A according to the second embodiment can simultaneously detect the temperature and the concentration of the absorber, the infrared detection device 10A can be used as a device for measuring the substantial temperature or the comfort index calculated from the temperature of the object 20 and the concentration of the absorber. It is suitable. For example, by detecting the temperature and the humidity at the same time, the substantial temperature calculated from the temperature and the humidity can be measured. The substantial temperature includes, for example, a sensible temperature, which is a temperature felt by a person, and an effective heating temperature applied to food by a cooking device. Generally, as the temperature and humidity of the object 20 increase, the substantial temperature increases.

A suitable wavelength for calculating the substantial temperature will be described. As described above, in the second embodiment, when the temperature of the object 20 changes, the ratio of the black body spectral radiance changes slightly, so that a calculation error occurs in the temperature and the transmittance of the object 20. That is, the accuracy of calculating the temperature and the transmittance of the object 20 depends on the accuracy of dividing the ratio of the black body spectral radiance and the ratio of the transmittance.

On the other hand, even if the difference between the temperature of the object 20 and the transmittance is accompanied by an error, the substantial temperature can be calculated with high accuracy. For example, regardless of whether the value of temperature or humidity is increased, under the condition that the ratio of the spectral irradiance increases, the calculation error due to the carving can be canceled out, so that the actual temperature must be calculated with high accuracy. You can In other words, the temperature and humidity are not sufficiently separated due to experimental error and deviation from the transmission model, and even if the humidity is calculated higher (lower) than it actually is, the temperature is calculated lower (higher), so The conversion reduces the calculation error. In other words, the substantial temperature can be calculated with high accuracy by selecting the wavelength so that the correlation between the substantial temperature and the ratio of the spectral irradiance becomes large.

When the detection wavelengths λ ₂ and λ ₃ are set to λ ₂ <λ ₃ according to the second embodiment, when the temperature of the object 20 increases, the blackbody spectral radiation of the detection wavelengths λ ₂ and λ ₃ is caused by the property of Planck's equation. The illuminance ratio (B(λ ₂ , T)/B(λ ₃ , T)) increases. In other words, as the temperature of the object 20 increases, the ratio of the spectral irradiance detected by the detectors 2 and 3 (I(λ ₂ , T)/I(λ ₃ , T)) increases.

Therefore, if the wavelengths λ ₂ and λ ₃ where the transmittance ratio (τ(λ ₂ )/τ(λ ₃ )) increases with respect to the increase in humidity are selected, they are detected by the detector 2 and the detector 3. The ratio of the spectral irradiance (I(λ ₂ , T)/I(λ ₃ , T)) also increases, and the substantial temperature calculation error due to the temperature/humidity separation error is reduced.

Here, a schematic diagram of the relationship between the transmittance of water vapor and the wavelength at a certain humidity is shown in FIG. In the wavelength region of 3.0 to 16 μm, the water vapor transmission rate can be classified into three types: a high transmission rate region, a first low transmission rate region, and a second low transmission rate region. The high transmittance region is a wavelength region showing a high transmittance of 3.5 to 4.5 μm and 8.0 to 13.0 μm. The first low transmittance region is a low transmittance region of 3.0 to 3.5 μm and 6.0 to 8.0 μm and a wavelength region where the transmittance increases as the wavelength becomes longer. The second low transmittance region is a low transmittance region of 4.5 to 6.0 μm and 13.0 to 16.0 μm and a wavelength region where the transmittance decreases as the wavelength becomes longer.

According to the Lambert-Beer law shown in the equation (4), there is a negative correlation between the transmittance and the extinction coefficient at the same absorber concentration. That is, the wavelength condition in which the transmittance ratio (τ(λ ₂ )/τ(λ ₃ )) increases with an increase in humidity satisfies τ(λ ₂ )>τ(λ ₃ ) in FIG. Wavelength. That is, when the detection wavelength λ ₂ belongs to the high transmittance region and the detection wavelength λ ₃ belongs to the adjacent low transmittance region (that is, the second low transmittance region), and the detection wavelengths λ ₂ and λ ₃ are This is the case where they belong to the same second low transmittance region.

That is, when the detection wavelength λ ₂ is in the range of 3.5 to 4.5 μm and the detection wavelength λ ₃ is in the range of 4.5 to 6.0 μm, the substantial temperature can be calculated with high accuracy. it can. Alternatively, when the detection wavelength λ ₂ belongs to the range of 8.0 to 13.0 μm and the detection wavelength λ ₃ belongs to the range of 13.0 to 16.0 μm, the substantial temperature can be calculated with high accuracy. .. Alternatively, when the detection wavelengths λ ₂ and λ ₃ belong to the range of 4.5 to 6.0 μm, the substantial temperature can be calculated with high accuracy. Alternatively, when the detection wavelengths λ ₂ and λ ₃ belong to the range of 13.0 to 16.0 μm, the substantial temperature can be calculated with high accuracy.

Regarding the calculation of the substantial temperature, the calculation parameter for directly calculating the substantial temperature from the spectral irradiance of the detection wavelengths λ ₂ and λ ₃ is used instead of the brightness ratio parameter 43 and the transmittance calculation tables 42 and 45. It may be arranged in the calculation unit 4A.
(Effects of radiation thermometer and gas sensor for measuring comfort index)
The comfort index may be calculated based on the temperature and the carbon dioxide concentration or the temperature and the aerosol concentration, instead of the actual temperature. Thus, the user, the cooking device, the ventilation device, the air conditioning device, and the air purifier can perform feed back by making a judgment based on the substantial temperature and the index of comfort.

With respect to the comfort index that decreases when the temperature and the carbon dioxide concentration increase, a suitable wavelength will be described. Similar to the case of the substantial temperature, the condition that can reduce the error in separating the temperature of the object 20 and the transmittance is that the ratio of the transmittance (τ(λ ₂ )/τ( with respect to the increase of the carbon dioxide concentration). There are two detection wavelengths that increase λ ₃ )).

Here, a schematic diagram of the relationship between the carbon dioxide transmittance and the wavelength at a certain humidity is shown in FIG. 11. In the case of carbon dioxide transmittance, the wavelength range of 3.0 to 16 μm can be classified into three types: a high transmittance area, a second low transmittance area, and a third low transmittance area. The high transmittance region is a wavelength region showing a high transmittance of 3.5 to 4.0 μm and 4.5 to 13.5 μm. The second low transmittance region is a low transmittance region of 13.5-16.0 μm and a wavelength region in which the transmittance decreases as the wavelength becomes longer. The third low transmittance region is a wavelength region showing a low transmittance of 4.0 to 4.5 μm.

According to the Lambert-Beer law shown in the equation (4), there is a negative correlation between the transmittance and the extinction coefficient at the same absorber concentration. That is, the wavelength condition in which the transmittance ratio (τ(λ ₂ )/τ(λ ₃ )) increases with increasing humidity satisfies τ(λ ₂ )>τ(λ ₃ ) in FIG. 11. Wavelength. That is, when the detection wavelength λ ₂ belongs to the high transmittance region and the detection wavelength λ ₃ belongs to the adjacent low transmittance region (that is, the second low transmittance region), and the detection wavelengths λ ₂ and λ ₃ Belong to the same second low transmittance region.

That is, when the detection wavelength λ ₂ is in the range of 3.5 to 4.0 μm and the detection wavelength λ ₃ is in the range of 4.0 to 4.5 μm, the comfort index can be calculated with high accuracy. it can. Alternatively, when the detection wavelength λ ₂ belongs to the range of 4.5 to 13.5 μm and the detection wavelength λ ₃ belongs to the range of 13.5 to 16.0 μm, the comfort index can be calculated with high accuracy. .. Alternatively, when the detection wavelengths λ ₂ and λ ₃ belong to the range of 13.5 to 16.0 μm, the comfort index can be calculated with high accuracy.

Regarding the calculation of the comfort index, the brightness ratio parameter 43 and the transmittance calculation tables 42 and 45 are replaced by calculation parameters for directly calculating the comfort index from the spectral irradiance of the detection wavelengths λ ₂ and λ _3. It may be arranged in the calculation unit 4A.
(Effects of Application of Second Embodiment)
By forming the infrared detection device 10A according to the second embodiment into an array, it can be used as an infrared camera. The infrared camera to which the infrared detection device 10A according to the second embodiment is applied can simultaneously capture both an image regarding the temperature of the object 20 and an image regarding the absolute amount of the absorber. With this function, the contour and distribution of the object 20 can be determined with higher accuracy.

The other description of the second embodiment is the same as that of the first embodiment.

[Third Embodiment]
FIG. 15 is a schematic diagram of an infrared detection device according to the third embodiment. Referring to FIG. 15, an infrared detection device 10B according to the third embodiment is the same as infrared detection device 10 except that calculation unit 4 of infrared detection device 10 shown in FIG. 1 is replaced with calculation unit 4B. Is.

The calculation unit 4B is the same as the calculation unit 4 except that the transmittance calculation table 42 of the calculation unit 4 shown in FIG.

Emissivity calculation table 46, with respect to such material structure and surface condition of the object 20, the ratio ε (λ ₃₎ of emissivity / ε (λ ₂₎ and the relationship between the numerical values of emissivity ε (λ ₂₎ ( Or the relationship between the emissivity ratio ε(λ ₂ )/ε(λ ₃ ) and the numerical value of the emissivity ε(λ ₃ ).

The emissivity calculation table 46 may be calculated by an experimental spectrum regarding emissivity or its fitting, or may be calculated by a theoretical formula regarding emissivity. Further, the emissivity calculation table 46 does not necessarily have to be the relationship between the ratio of the emissivity and the numerical value of the emissivity, and may be a relational expression of the ratio of the emissivity and the emissivity including a calculation parameter.

In the third embodiment, the detection ratio α and the transmittances τ(λ ₂ ) and τ(λ ₃ ) are known.

When the two wavelengths λ ₂ and λ ₃ are selected by the wavelength selection unit 44, the calculation unit 4B receives the spectral irradiances I(λ ₂ , T), I(λ ₃ , T from the detectors 2 and 3, respectively. ), known transmittances τ(λ ₂ ), τ(λ ₃ ) and known black body spectral radiance ratio approximations R _est are substituted into equation (10) to give emissivity ratios ε(λ ₂ )/ε(λ ₃ ) is calculated.

The calculation unit 4B, by detecting the ratio of emissivity based on emissivity calculation table 46 ε (λ ₂₎ / ε emissivity corresponding to _{(λ 3) ε (λ 2} ), the ratio of the emissivity The emissivity ε(λ ₂ ) is calculated from ε(λ ₂ )/ε(λ ₃ ).

After that, the calculation unit 4B calculates the known detection ratio α, the known transmittance τ(λ ₂ ), the calculated emissivity ε(λ ₂ ) and the spectral irradiance I(λ ₂ , T) by the formula (1). To calculate the blackbody spectral radiance B(λ ₂ , T).

Then, the calculation unit 4B calculates the temperature T of the target object 20 by substituting the calculated black body spectral radiance B(λ ₂ , T) into the equation (2).

If the cause of the change in the emissivity of the object 20 is known, the change in the material composition and the surface state can be known as the change in the emissivity of the object 20 through the change in the emissivity of the object 20. Therefore, the infrared detection device 10B also functions as a determiner that determines what the target object 20 is, or a determiner that determines the state of the target object 20.

FIG. 16 is a flowchart showing a detection method for detecting the temperature of the target object 20 according to the third embodiment. The flowchart shown in FIG. 16 is the same as the flowchart shown in FIG. 3 except that steps S3 to S7 of the flowchart shown in FIG. 3 are changed to steps S41 to S44.

Referring to FIG. 16, when the operation of detecting the temperature is started, steps S1 and S2 described above are sequentially executed.

Then, after step S2, the calculation unit 4B causes the spectral irradiances I(λ ₂ , T) and I(λ ₃ , T) received from the detectors 2 and 3, respectively, and the known transmittance τ(λ ₂ ). , Τ(λ ₃ ) and the approximate value R _est of the ratio of the black body spectral irradiation luminance are substituted into the equation (10) to calculate the emissivity ratio ε(λ ₃ )/ε(λ ₂ ) (step S41). ..

Then, calculating unit 4B is calculated emissivity ratios ε (λ ₃₎ / ε is calculated emissivity epsilon a (lambda ₂₎ on the basis of (lambda ₂₎ (step S42). More specifically, the calculation unit 4B, the radiation by detecting the ratio of the emissivity based on the emissivity calculation table 46 ε (λ ₃₎ / ε emissivity corresponding to _{(λ 2) ε (λ 2} ) The emissivity ε(λ ₂ ) is calculated from the ratio ε(λ ₃ )/ε(λ ₂ ).

After step S42, the calculation unit 4B calculates the known detection ratio α, the measured spectral irradiance I(λ ₂ , T), the known transmittance τ(λ ₂ ), and the calculated emissivity ε(λ. ₂ ) is substituted into the equation (1) to calculate the black body spectral radiance B(λ ₂ , T) (step S43).

Then, the calculation unit 4B calculates the temperature of the target object 20 by substituting the calculated black body spectral radiance B(λ ₂ , T) into the equation (2) (step S44). As a result, the operation of detecting the temperature of the object 20 ends.

In the flowchart shown in FIG. 16, the emissivity ratio ε(λ ₃ )/ε(λ ₂ ) is calculated based on the spectral irradiances I(λ ₂ , T) and I(λ ₃ , T), and the calculation is performed. the ratio of the emissivity _{ε (λ 3) / ε (} λ 2) to calculate the emissivity ε (λ ₂₎ from the calculated emissivity ε (λ ₂₎ from the blackbody spectral radiance B (lambda _2, T ) Was calculated to calculate the temperature of the object 20. However, the third embodiment is not limited to this, and the emissivity ratio ε(λ ₂ )/ based on the spectral irradiances I(λ ₂ , T) and I(λ ₃ , T) is not limited to this by the formula (11). calculated epsilon a (λ _3), the calculated emissivity ratios ε (λ ₂₎ / ε may be calculated emissivity epsilon a (lambda ₃₎ from (lambda _3). In this case, the temperature of the target object 20 can be calculated by calculating the blackbody spectral radiance B(λ ₃ , T) from the calculated emissivity ε(λ ₃ ). In this case, in the flowchart shown in FIG. 16, “emissivity ratio ε(λ ₃ )/ε(λ ₂ )” is replaced with “emissivity ratio ε(λ ₂ )/ε(λ ₃ )” and The rate ε(λ ₂ ) is read as “emissivity ε(λ ₃ )”, the “spectral irradiance I(λ ₂ , T)” is read as “spectral irradiance I(λ ₃ , T)”, and “black” is displayed. The “body spectral radiance B(λ ₂ , T)” may be read as “black body spectral radiance B(λ ₃ , T)”.

Therefore, the method for detecting the temperature of the object 20 according to the third embodiment is based on the spectral irradiances I(λ ₂ , T), I(λ ₃ , T), and the emissivity ε(λ ₂ ), ε(λ ₃ the ratio was calculated for), emissivity and the calculated epsilon (lambda _2), the emissivity from the ratio of _{ε (λ 3) (ε (} λ 2), one of epsilon (lambda ₃₎₎ is calculated, the calculated The temperature of the object 20 may be calculated from the emissivity (one of ε(λ ₂ ) and ε(λ ₃ )).

In addition, in the third embodiment, the operation of detecting the temperature of the target object 20 may be executed by software. In this case, the calculation unit 4B includes a CPU, ROM and RAM.

The ROM receives step S1-1A that receives the spectral irradiance I(λ ₁ , T), the spectral irradiance I(λ ₂ , T), and the spectral irradiance I(λ ₃ , T) from the detectors 1 to 3, respectively. Emissivity ε(λ ₁ ), ε(λ ₂ ), ε(λ ₃ ) and extinction coefficients ε _a (λ ₁ ), ε _a (λ ₂ ), ε _a (λ ₃ ) via an input device (keyboard or the like). ) Is received, and a program Prog_F including steps S2 and S41 to S44 shown in FIG. 16 is stored. The ROM also stores the brightness ratio parameter 43 and the emissivity calculation table 46 shown in FIG. The RAM has the spectral irradiances I(λ ₁ , T), I(λ ₂ , T), I(λ ₃ , T), emissivity ε(λ ₁ ), ε(λ ₂ ), ε received by the CPU. (Λ ₃ ) and extinction coefficient ε _a (λ ₁ ), ε _a (λ ₂ ), ε _a (λ ₃ ), an approximate value R _est of the ratio of the black body spectral radiance detected by the CPU, calculated by the CPU The emissivity ratio ε(λ ₃ )/ε(λ ₂ ), the emissivity ratio ε(λ ₃ )/ε(λ ₂ ) calculated by the CPU based on the emissivity ratio ε(λ ₃ )/ε(λ ₂ ), and the CPU The blackbody spectral radiance B(λ ₂ , T) calculated by is temporarily stored.

The CPU reads the program Prog_F from the ROM, sequentially executes steps S1-1A, S1-2A, S2, S41 to S44 of the read program Prog_F, and detects the temperature of the object 20 by the method described above.

In this case, the CPU that detects the approximate value R _est of the black body spectral radiance ratio constitutes “detection means”, and the emissivity ratio ε(λ ₃ )/ε(λ ₂ ) and the emissivity ε(λ ₂ ) and the CPU that calculates the temperature T constitute "calculation means". Further, spectral irradiances I(λ ₁ , T), I(λ ₂ , T), I(λ ₃ , T), emissivity ε(λ ₁ ), ε(λ ₂ ), ε(λ ₃ ) and absorption The CPU that receives the coefficients ε _a (λ ₁ ), ε _a (λ ₂ ), and ε _a (λ ₃ ) constitutes “reception means”.

Further, the program Prog_F may be recorded in a recording medium (for example, CD and DVD) and distributed. In this case, the computer (CPU) reads the program Prog_F from the recording medium and executes it to detect the temperature of the object 20. Therefore, a CD, a DVD, or the like in which the program Prog_F is recorded is a computer (CPU) readable recording medium in which the program Prog_F is recorded.

[Effects of Third Embodiment]
The effects of the third embodiment will be described.
(Effects of radiation thermometer)
The infrared detection device 10B according to the third embodiment has an emissivity correction function that is not provided in a conventional emissive thermometer, and calculates the temperature with high accuracy even for an object 20 whose emissivity is not always constant. You can That is, for example, even if the surface state or the chemical composition of the target object 20 can change, it is possible to calculate the temperature with high accuracy.

Thereby, for example, the temperature of the object 20 (organic substance, metal, ceramic, etc.) undergoing a chemical reaction such as decomposition or chemical compound can be measured with high accuracy. That is, the user can estimate the temperature of the target 20 during the chemical reaction with high accuracy and adjust the temperature of the target 20 by using the infrared detection device 10B according to the third embodiment. is there.
(Effects on emissivity detector and radiation thermometer)
The infrared detection device 10B according to the third embodiment can detect the surface state of the target object 20 by calculating the emissivity of the target object 20.

Thereby, for example, in an environment where the surface state of the target object 20 changes, a roughness measuring device based on the surface roughness of the target object 20 or a deterioration sensor for measuring the degree of deterioration due to the surface roughness of the target object 20. It can be used as

Further, the user can judge the surface condition of the target object 20 and feed it back by using the infrared detection device 10B according to the third embodiment.

Further, by using the infrared detection device 10B according to the third embodiment to measure changes over time in both the surface state and the temperature, it is possible to predict the progress of deterioration with higher accuracy than with existing deterioration sensors. ..

Furthermore, the infrared detection device 10B according to the third embodiment can detect the chemical composition of the target object 20 by calculating the emissivity of the target object 20. Thereby, for example, in an environment where the chemical composition of the target object 20 changes, the infrared detection device 10B can be used as a composition analysis instrument. Further, the user can judge the surface condition of the target object 20 and feed it back by using the infrared detection device 10B according to the third embodiment. Further, according to the infrared detection device 10B according to the third embodiment, both chemical composition and temperature can be detected, so that a compact and low-cost composition analysis device and thermometer can be constructed.
(Effects of Application of Third Embodiment)
As described above, since the detectors 2 and 3 may be the same detector, it is necessary to apply a large voltage particularly when the two detection wavelengths λ ₂ and λ ₃ are close to each other as in the third embodiment. Therefore, it is possible to operate at high speed with low power consumption and obtain the effect in the first embodiment.

Further, by forming the infrared detection device 10B according to the second embodiment into an array, it can be used as an infrared camera. An infrared camera to which the infrared detection device 10B is applied can simultaneously capture both an image relating to the temperature of the object 20 and an image relating to the material composition and surface state. With this function, the contour of the object 20 can be determined with higher accuracy.

The other description in the third embodiment is the same as the description in the first embodiment.

In the first to third embodiments described above, the effect was confirmed when the detection wavelength was set to 8.5 μm, 13.0 μm, and 13.5 μm, but the same effect is obtained even when another detection wavelength is used. Needless to say.

FIG. 17 is a schematic diagram of an infrared detection device for detecting the temperature distribution of an object according to the embodiment of the present invention.

With reference to FIG. 17, the infrared detection device 100 includes a lens 110, detector groups 120-1 to 120-N (N is an integer of 2 or more), and a calculation unit 130.

The lens 110 focuses the infrared light emitted from the region REG_1 of the object 20 on the detector group 120-1. In addition, the lens 110 focuses the infrared light emitted from the region REG_2 of the target object 20 on the detector group 120-2. Thereafter, similarly, the lens 110 focuses the infrared rays emitted from the region REG_N of the object 20 on the detector group 120-N.

Each of the detector groups 120-1 to 120-N has, for example, a configuration in which the two detectors 2 and 3 in the first embodiment are arranged one-dimensionally or two-dimensionally. Then, the detector group 120-1 detects the spectral irradiance I _{REG_1} (λ ₂ , T), I _{REG_1} (λ ₃ , T) of the infrared rays condensed by the lens 110, and the detected spectral irradiance I. _{REG_1} (λ ₂ , T), I _{REG_1} (λ ₃ , T) is output to the calculation unit 130. Further, the detector group 120-2 detects the spectral irradiance I _{REG_2} (λ ₂ , T), I _{REG — 2} (λ ₃ , T) of the infrared light condensed by the lens 110, and the detected spectral irradiance I. _{REG_2} (λ ₂ , T), I _{REG_2} (λ ₃ , T) is output to the calculation unit 130. Thereafter, similarly, the detector group 120-N detects the spectral irradiances I _{REG_N} (λ ₂ ,T) and I _{REG_N} (λ ₃ ,T) of the infrared rays condensed by the lens 110, and detects them. The spectral irradiances I _{REG_N} (λ ₂ , T) and I _{REG — N} (λ ₃ , T) are output to the calculation unit 130.

The calculation unit 130 includes N calculation units 130-1 to 130-N. Calculation units 130-1 to 130-N are provided corresponding to detector groups 120-1 to 120-N, respectively. Each of the calculation units 130-1 to 130-N is, for example, the calculation unit 4 according to the first embodiment.

The calculation unit 130-1 receives the spectral irradiances I _{REG_1} (λ ₂ , T) and I _{REG — 1} (λ ₃ , T) from the detector group 120-1, and receives the received spectral irradiance I _{REG — 1} (λ ₂ , T). ), I _{REG_1} (λ ₃ ,T) and the temperature T _{REG_1} in the region REG_1 of the object 20 and the region REG_1 of the object 20 to the detector group 120-1 by the method in the first embodiment described above. Infrared transmittance τ _{REG — 1} (λ ₂ ) between is calculated.

The calculation unit _130-2 receives the spectral irradiances I _{REG — 2} (λ ₂ , T) and I _{REG — 2} (λ ₃ , T) from the detector group 120-2, and receives the received spectral irradiance I _{REG — 2} (λ ₂ , T). ), I _{REG_2} (λ ₃ , T) and the temperature T _{REG_2} in the region REG_2 of the object 20 and the region REG_2 of the object 20 to the detector group 120-2 by the method in the above-described first embodiment. Infrared transmittance τ _{REG — 2} (λ ₂ ) is calculated.

Hereinafter, similarly, the calculation unit 130-N receives the spectral irradiances I _{REG_N} (λ ₂ , T) and I _{REG_N} (λ ₃ , T) from the detector group 120-N, and receives the received spectral irradiance I. _{REG_N (λ 2, T),} based on the _{I REG_N (λ 3, T)} , the temperature the temperature _{T REG_N} in the region REG_N of the object 20 by the method according to the first embodiment described above, and detected from the area REG_N object 20 Infrared transmittance τ _REG — N (λ ₁ ) up to the device group 120-N is calculated.

The calculation unit 130, based on the calculation unit 130-1～ temperature _T are respectively calculated by the calculating unit 130-N REG_1 _{~T REG_N,} and transmittance _{τ REG_1 (λ 1) ~τ REG_N} (λ 1), The distribution of the temperature and the transmittance of the object 20 is calculated. Here, the distribution of the temperature and the emissivity of the target object 20 is calculated using the known emissivity of the target object 20.

In the infrared detection device 100, each of the detector groups 120-1 to 120-N has a configuration in which the three detectors 1 to 3 according to the second embodiment are arranged one-dimensionally or two-dimensionally, and the calculation unit 130. Each of −1 to 130-N may be configured by the calculation unit 4A, and each of the detector groups 120-1 to 120-N may have the two detectors 2 and 3 of the third embodiment arranged one-dimensionally or two-dimensionally. Each of the calculation units 130-1 to 130-N may be composed of the calculation unit 4B. In such a case, the calculation unit 130 (calculation units 130-1 to 130-N) calculates the distribution of the temperature and the transmittance of the target object 20 by the method in the above-described second embodiment or third embodiment.

Further, the calculation unit 130 does not have to include N calculation units 130-1 to 130-N. In this case, the calculation unit 130 receives the spectral irradiances I _{REG_1} (λ ₂ , T), I _{REG — 1} (λ ₃ , T), and the spectral irradiance I _{REG — 2} (λ) received from the detector groups 120-1 to ₁₂₀ -N, respectively. ₂ , T), I _{REG — 2} (λ ₃ , T),..., Spectral irradiance I _{REG — N} (λ ₂ , T), I _{REG — N} (λ ₃ , T) based on the method and implementation in the first embodiment The distribution of the temperature and the transmittance of the object 20 is calculated using either the method according to the second embodiment or the method according to the third embodiment.

Furthermore, the operation of the calculation unit 130 (calculation units 130-1 to 130-N) may be executed by any of the programs Prog_A to Prog_F described above.

As described above, by using the infrared detection device 100, the distribution of the temperature and the transmittance of the object 20 can be calculated.

FIG. 18 is a flowchart for explaining the operation of the infrared detection device 100 shown in FIG.

With reference to FIG. 18, when the operation of the infrared detection device 100 is started, the detector group 120-1 and the calculation unit 130-1 are the flowchart shown in FIG. 3, the flowchart shown in FIG. 6, and the flowchart shown in FIG. And the temperature T _{REG_1} and the transmittance τ _{REG_1} of the object 20 are calculated by any of the flowcharts shown in FIG. 16 (step S101-1).

In addition, the detector group 120-2 and the calculation unit _{130-2 perform} the temperature T _{REG_2 of the} target object 20 by any one of the flowchart shown in FIG. 3, the flowchart shown in FIG. 6, the flowchart shown in FIG. 13, and the flowchart shown in FIG. And the transmittance τ _{REG_2} is calculated (step S101-2).

Hereinafter, in the same manner, the detector group 120-N and the calculation unit 130-N perform the object 20 according to any one of the flowchart shown in FIG. 3, the flowchart shown in FIG. 6, the flowchart shown in FIG. 13, and the flowchart shown in FIG. The temperature T _{REG_N} and the transmittance τ _{REG_N} are calculated (step S101-N).

The calculation unit 130, based on the temperature _T REG_1 _{~T REG_N} and transmittance τ _{REG_1} ~τ _{REG_N} object 20, calculates the distribution of the temperature and transmittance of the object 20 (step S102). As a result, the operation of the infrared detection device 100 ends.

When the flowchart shown in FIG. 3 or the flowchart shown in FIG. 13 is used in each of steps S101-1 to S101-N, each of the calculation units 130-1 to 130-N causes the spectral radiation detected by the detector 2 to be detected. Spectral irradiance ratio I(λ ₂ ,T)/I(λ ₃ ,T) between illuminance I(λ ₂ ,T) and spectral irradiance I(λ ₃ ,T) detected by detector 3 and black body The transmittance ratio τ(λ ₂ )/τ(λ ₃ ) is calculated based on the approximate value R _est of the spectral radiance ratio, and the calculated transmittance ratio τ(λ ₂ )/τ(λ ₃ ) The transmittance τ(λ ₂ ) is calculated based on the above, and the temperature of the object 20 is calculated based on the calculated transmittance τ(λ ₂ ).

Therefore, the calculation units 130-1 to 130-N perform step S101-1 to S101-N based on the spectral irradiance ratio I(λ ₂ , T)/I(λ ₃ , T) and the approximate value R _est. The process of calculating the transmittance ratio τ(λ ₂ )/τ(λ ₃ ) is performed by N sets of spectral irradiance ratios I(λ ₂ , T), I(λ ₃ , T) was performed for calculating the ratio of N transmittance _{τ (λ 2) / τ (} λ 3), the ratio tau (lambda ₂ of N _{transmittance)} / τ (λ ₃₎ on the basis of N The transmittances τ(λ ₂ ) are calculated, and the temperatures N in the regions REG_1 to REG_N of the object 20 are calculated based on the transmittances τ(λ ₂ ).

Further, when the flowchart shown in FIG. 6 is used in each of steps S101-1 to S101-N, each of the calculation units 130-1 to 130-N has a spectral irradiance ratio I(λ ₂ , T)/I. Based on (λ ₃ ,T) and the approximation R _est , the root containing the ratio of extinction coefficients ε _a (λ ₃ )/ε _a (λ ₂ ) is used to calculate the square root of the estimated transmission ratio. Then, the temperature of the object 20 is calculated.

Therefore, the calculation units 130-1 to 130-N perform step S101-1 to S101-N based on the spectral irradiance ratio I(λ ₂ , T)/I(λ ₃ , T) and the approximate value R _est. , A square root of the estimated transmittance ratio is calculated using a root including the extinction coefficient ratio ε _a (λ ₃ )/ε _a (λ ₂ ), and the process of calculating the temperature of the target object 20 is performed. The N sets of spectral irradiance ratios I(λ ₂ , T) and I(λ ₃ , T) detected by the detector groups are executed to calculate N temperatures of the object 20.

Furthermore, in each of steps S101-1 to S101-N, when the flowchart shown in FIG. 16 is used, each of the calculation units 130-1 to 130-N causes the spectral irradiance I(λ ₂ , T) and the spectral irradiance I(λ ₃ , T) detected by the detector 3 and the spectral irradiance ratio I(λ ₂ , T)/I(λ ₃ , T) and the blackbody spectral radiance The emissivity ratio ε(λ ₃ )/ε(λ ₂ ) is calculated based on the approximate value R _est of the ratio, and the radiation is performed based on the calculated emissivity ratio ε(λ ₃ )/ε(λ ₂ ). The rate ε(λ ₂ ) is calculated, and the temperature of the object 20 is calculated based on the calculated emissivity ε(λ ₂ ).

Therefore, the calculation units 130-1 to 130-N perform step S101-1 to S101-N based on the spectral irradiance ratio I(λ ₂ , T)/I(λ ₃ , T) and the approximate value R _est. , The emissivity ratio ε(λ ₃ )/ε(λ ₂ ) is calculated by N sets of spectral irradiance ratios I(λ ₂ , T), I(λ ₃ ) detected by N detector groups. , the ratio epsilon (lambda ₃ of N emissivity was performed for _{T)) / ε (λ 2} ) to calculate the ratio epsilon (lambda ₃ of N _emissivity) / epsilon based on (lambda ₂₎ The N emissivities ε(λ ₂ ) are calculated, and the N temperatures of the object 20 are calculated based on the calculated N emissivities ε(λ ₂ ).

In the infrared detection device 100, the operation of detecting the temperature distribution of the object 20 may be executed by software. In this case, each of the calculation units 130-1 to 130-N includes a CPU, a ROM and a RAM.

The ROM stores any of the programs Prog_A, Prog_D, Prog_E, and Prog_F described above. The other description is the same as the description about the programs Prog_A, Prog_D, Prog_E, and Prog_F described above.

In the first embodiment described above, first, the spectral irradiance I(λ ₂ , T), I(λ ₃ , T) of infrared rays having wavelengths λ ₂ , λ ₃ longer than the peak wavelength λ _max , and the black body It has been explained that the transmittance ratio τ(λ ₂ )/τ(λ ₃ ) (or τ(λ ₃ )/τ(λ ₂ )) is calculated based on the approximate value R _est of the ratio of the spectral radiance. .. Next, from the calculated transmittance ratio τ(λ ₁ )/τ(λ ₂ )(or τ(λ ₃ )/τ(λ ₂ )), the transmittance τ(λ ₂ ) (or τ(λ ₃ ) ) Is calculated. Finally, it has been described that the temperature of the object 20 and/or the absolute amount or concentration of the absorber ABS is calculated based on the calculated transmittance τ(λ ₁ ) (or τ(λ ₃ )).

In the second embodiment described above, first, the infrared spectral irradiances I(λ ₂ , T), I(λ ₃ , T) having wavelengths λ ₂ , λ ₃ longer than the peak wavelength λ _max , The transmittance ratio τ(λ ₂ )/τ(λ ₃ ) (or τ(λ ₃ )/τ(λ ₂ )) is calculated based on the approximate value R _est of the ratio of the blackbody spectral radiance. explained. Next, from the calculated transmittance ratio τ(λ ₁ )/τ(λ ₂ )(or τ(λ ₃ )/τ(λ ₂ )), the transmittance τ(λ ₂ ) (or τ(λ ₃ ) ) Is calculated. Finally, the transmittance τ(λ ₁ ) is calculated from the calculated transmittance τ(λ ₂ ) (or τ(λ ₃ )), and the object 20 is calculated based on the calculated transmittance τ(λ ₁ ). Of temperature and/or calculating the absolute amount or concentration of absorber ABS.

Further, in the above-described third embodiment, first, infrared spectral irradiances I(λ ₂ , T), I(λ ₃ , T) having wavelengths λ ₂ , λ ₃ longer than the peak wavelength λ _max , The emissivity ratio ε(λ ₃ )/ε(λ ₂ ) (or τ(λ ₂ )/τ(λ ₃ )) is calculated based on the approximate value R _est of the black body spectral radiance ratio. explained. Next, from the calculated emissivity ratio ε(λ ₃ )/ε(λ ₂ )(or τ(λ ₂ )/τ(λ ₃ )), the emissivity ε(λ ₂ ) (or ε(λ ₃ )) ) Is calculated. Finally, it has been described that the temperature of the object 20 is calculated based on the calculated emissivity ε(λ ₂ ) (or ε(λ ₃ )).

As described above, in the first and second embodiments, the transmittance is based on the spectral irradiances I(λ ₂ , T), I(λ ₃ , T) and the approximate value R _est of the ratio of the blackbody spectral radiance. The ratio τ(λ ₂ )/τ(λ ₃ ) (or τ(λ ₃ )/τ(λ ₂ )) is calculated, and the calculated transmittance ratio τ(λ ₁ )/τ(λ ₂ )( Alternatively, the temperature of the object 20 is calculated based on τ(λ ₃ )/τ(λ ₂ )). In the third embodiment, the emissivity ratio ε( is based on the spectral irradiances I(λ ₂ , T), I(λ ₃ , T) and the approximate value R _{est of} the black body spectral radiance ratio. λ ₃ )/ε(λ ₂ ) (or τ(λ ₂ )/τ(λ ₃ )) is calculated, and the calculated emissivity ratio ε(λ ₃ )/ε(λ ₂ ) (or τ(λ 2 The temperature of the object 20 is calculated based on ₂ )/τ(λ ₃ )). Here, the transmittances τ(λ ₁ ), τ(λ ₂ ), and τ(λ ₃ ) are, as described above, the spectral radiance emitted by the object 20 through the optical path to the detectors 2, 3 (or detection). This is the rate of propagation to devices 1 to 3). Further, the emissivities ε(λ ₁ ), ε(λ ₂ ), and ε(λ ₃ ) are, as described above, the thermal radiation at the wavelengths λ ₁ , λ ₂ , and λ _{3 with} respect to the blackbody spectral radiance. It is the ratio of the spectral radiance emitted by the object 20. As a result, the transmittance ratio τ(λ ₂ )/τ(λ ₃ )(or τ(λ ₃ )/τ(λ ₂ )) and the emissivity ratio ε(λ ₃ )/ε(λ ₂ ) (or τ(λ ₂ )/τ(λ ₃ )) corresponds to the characteristic value of the spectral radiance.

Therefore, in the first embodiment, the second embodiment, and the third embodiment, the characteristic value of the spectral radiance is calculated, and the temperature of the object 20 is calculated based on the calculated characteristic value of the spectral radiance. Characterize.

Therefore, according to the embodiment of the present invention, the infrared detection device detects the first spectral irradiance of the first infrared light having the first wavelength longer than the wavelength at which the black body spectral radiance is maximum. A first detector for detecting a second spectral irradiance of a second infrared ray having a second wavelength longer than the first wavelength, a first spectral irradiance Based on a first spectral irradiance ratio, which is a ratio with the spectral irradiance of 2, and an approximate value of the ratio between the black body spectral radiance at the first wavelength and the black body spectral radiance at the second wavelength. , A calculation unit that calculates the characteristic value of the spectral radiance at the first and second wavelengths and calculates the temperature of the object based on the calculated characteristic value of the spectral radiance.

Further, according to the embodiment of the present invention, the infrared detection method includes a first spectral irradiance of a first infrared ray having a first wavelength longer than a wavelength at which the black body spectral radiance has a maximum value, A first step of detecting a second spectral irradiance of a second infrared ray having a second wavelength longer than the first wavelength, and a ratio of the first spectral irradiance and the second spectral irradiance The first and second wavelengths based on the first spectral irradiance ratio which is the ratio of the black body spectral radiance at the first wavelength to the black body spectral radiance at the second wavelength. The second step of calculating the characteristic value of the spectral radiance in the above and the third step of calculating the temperature of the object on the basis of the calculated characteristic value of the spectral radiance.

Further, according to the embodiment of the present invention, the program is such that the receiving means sets the first spectral irradiance of the first infrared ray having the first wavelength and the second wavelength longer than the first wavelength. A first step of receiving the second spectral irradiance of the second infrared ray which is included; And a characteristic value of the spectral radiance at the first and second wavelengths based on an approximate value of the ratio of the black body spectral radiance at the first wavelength and the black body spectral radiance at the second wavelength. The computer may execute the second step of performing the calculation and the third step of calculating the temperature of the object based on the calculated characteristic value of the spectral radiance.

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

The present invention is applied to an infrared detection device, an infrared detection method, a program to be executed by a computer, and a computer-readable recording medium recording the program.

1 to 3 detector, 4, 4A, 4B, 130, 130-1 to 130-N calculation unit, 1010A, 10B, 100 infrared detection device, 20 object, 41 luminance table, 42, 45 transmittance calculation table , 43 luminance ratio parameter, 44 wavelength selection unit, 46 emissivity calculation table, 110 lens, 120-1 to 120-N detector group.

Claims (34)

A first detector for detecting a first spectral irradiance of a first infrared having a first wavelength;
A second detector for detecting a second spectral irradiance of a second infrared ray having a second wavelength longer than the first wavelength;
A first spectral irradiance ratio, which is a ratio of the first spectral irradiance and the second spectral irradiance, a blackbody spectral radiance at the first wavelength, and a blackbody spectrum at the second wavelength. The characteristic value of the spectral radiance at the first and second wavelengths is calculated based on the approximate value of the ratio with the radiance, and the temperature of the object is calculated based on the calculated characteristic value of the spectral radiance. Infrared detection device comprising: The infrared detection device according to claim 1, wherein the first wavelength and the second wavelength are longer than a wavelength at which the black body spectral radiance has a maximum value. The calculating unit is a transmittance of the first infrared ray between the object and the first and second detectors based on the first spectral irradiance ratio and the approximate value. The first transmittance ratio, which is the ratio of the second transmittance which is the transmittance of the second infrared ray between the object and the first and second detectors, to the characteristic Of the first transmittance ratio using a root calculated as a value and including an extinction coefficient ratio that is a ratio of the first extinction coefficient of the first infrared ray and the second extinction coefficient of the second infrared ray. The infrared detection device according to claim 1 or 2, wherein a square root is calculated to calculate a first calculated temperature, and the first calculated temperature is calculated as the temperature of the object. The infrared detection device according to claim 3, wherein the calculation unit calculates the first calculated temperature calculated by the following equation (1) as the temperature of the object.

[In the formula (1), h is Planck's constant, k is Boltzmann's constant, c is the speed of light, λ ₂ is the first wavelength, and λ ₃ is the second wavelength. Is a wavelength, α is a ratio of the spectral radiance emitted by the object detected by the first and second detectors, T _est1 is the first calculated temperature, and ε _a (Λ ₂ ) is the first extinction coefficient, ε _a (λ ₃ ) is the second extinction coefficient, and I(λ ₂ , T) is the first spectral irradiance. , I(λ ₃ , T) is the second spectral irradiance, R _est is the approximate value, and T is the absolute temperature. ] The infrared detector according to claim 3 or 4, wherein the calculator calculates a second calculated temperature obtained by correcting the first calculated temperature as the temperature of the object. The infrared detection device according to claim 5, wherein the calculation unit calculates a second calculated temperature corrected by the following equation (2) as the temperature of the object.

[In Formula (2), h is Planck's constant, k is Boltzmann's constant, c is the speed of light, λ ₂ is the first wavelength, and λ ₃ is the second wavelength. Wavelength, T _est1 is the first calculated temperature, T _est2 is the second calculated temperature, ε _a (λ ₂ ) is the first extinction coefficient, and ε _a ( λ ₃ ) is the second extinction coefficient, R _est is the approximate value, and R(T _est1 ) is the black body spectral radiance at the first calculated temperature and the first wavelength. , The ratio of the first calculated temperature and the blackbody spectral radiance at the second wavelength. ] Further comprising a third detector for detecting a third spectral irradiance of a third infrared having a third wavelength shorter than the first wavelength,
The calculator calculates a third transmittance, which is one of the first and second transmittances, from the first transmittance ratio, and calculates the first and second transmittances from the object. And a fourth transmittance, which is the transmittance of the third infrared ray between the third detector and the third detector, is calculated from the third transmittance, and the calculated fourth transmittance and the third transmittance are calculated. The infrared detection device according to claim 3, wherein the temperature of the object is calculated based on a rate. The calculation unit further calculates the absolute amount or concentration of the absorber existing between the object and the first and second detectors based on the characteristic value. Infrared detection device given in any 1 paragraph. The calculation unit further calculates the concentration of water vapor which is the absorber based on the characteristic value, and calculates a substantial temperature from the concentration of the water vapor and the temperature of the object,
The first wavelength is set in the range of 3.5 to 6.0 μm, and the second wavelength is set in the range of 4.5 to 6.0 μm,
Or
The infrared ray according to claim 8, wherein the first wavelength is set in a range of 8.0 to 16.0 μm, and the second wavelength is set in a range of 13.0 to 16.0 μm. Detection device. The calculation unit further calculates the concentration of carbon dioxide that is the absorber based on the characteristic value, and calculates the comfort index from the concentration of the carbon dioxide and the temperature of the object,
The first wavelength is set in the range of 3.5 to 4.0 μm, and the second wavelength is set in the range of 4.0 to 4.5 μm,
Or
The infrared ray according to claim 8, wherein the first wavelength is set in a range of 4.5 to 16.0 μm, and the second wavelength is set in a range of 13.5-16.0 μm. Detection device. The calculation unit emits radiation that is a ratio of a first emissivity at the first wavelength and a second emissivity at the second wavelength based on the first spectral irradiance ratio and the approximate value. The infrared detection device according to claim 1, wherein a rate ratio is calculated as the characteristic value, and the temperature of the object is calculated based on the calculated emissivity ratio. The calculating unit calculates a third emissivity that is one of the first and second emissivities based on the emissivity ratio, and based on the calculated third emissivity. The infrared detection device according to claim 11, which calculates the temperature of the object. Further comprising a wavelength selection unit for selecting the first and second wavelengths in the wavelength range from mid-infrared to far-infrared,
The wavelength selection unit holds an accuracy rating that defines the accuracy of the calculated temperature calculated by the calculation unit, and the temperature of the object in the measurement range of the temperature of the object and the calculated temperature of the object. The infrared detection device according to any one of claims 1 to 12, wherein the first and second wavelengths are selected so that the error of is smaller than the accuracy rating. Two or three detectors among the first to third detectors are the same detectors of quantum well type or quantum dot type,
The infrared detection device according to claim 7, wherein the infrared detection device further includes a control unit that controls a voltage applied to the same detector to control a wavelength to be detected. The first and second detectors arranged in an array form a detector group,
The calculation unit performs a process of calculating the characteristic value based on the first spectral irradiance ratio and the approximate value, and a plurality of sets of the first and second spectral radiation detected by the plurality of detector groups. The plurality of characteristic values are calculated by executing the illuminance, the plurality of temperatures in the plurality of regions of the object are calculated based on the calculated plurality of characteristic values, and the target is calculated based on the calculated plurality of temperatures. The infrared detection device according to claim 1, which calculates a temperature distribution of an object. The first to third detectors arranged in an array form a detector group,
The calculator executes a process of calculating the third transmittance from the first transmittance ratio for a plurality of sets of the first and second spectral irradiances detected by the plurality of detector groups. Calculate a plurality of third transmittances, calculate a plurality of the fourth transmittances from the plurality of third transmittances, calculate the plurality of third transmittances and the plurality of fourth transmittances. The infrared detection device according to claim 7, wherein a plurality of temperatures in a plurality of regions of the target object are calculated based on, and a temperature distribution of the target object is calculated based on the calculated plurality of temperatures. First to detect a first spectral irradiance of a first infrared ray having a first wavelength and a second spectral irradiance of a second infrared ray having a second wavelength longer than the first wavelength Steps of
A first spectral irradiance ratio, which is a ratio of the first spectral irradiance and the second spectral irradiance, a blackbody spectral radiance at the first wavelength, and a blackbody spectrum at the second wavelength. A second step of calculating a characteristic value of the spectral radiance at the first and second wavelengths based on an approximate value of a ratio with the radiance;
And a third step of calculating the temperature of the object based on the calculated characteristic value of the spectral radiance. The infrared detection method according to claim 17, wherein the first and second wavelengths are longer than a peak wavelength at which the maximum value of the black body spectral radiance is obtained. In the second step, it is a transmittance of the first infrared ray between the object and the first and second detectors based on the first spectral irradiance ratio and the approximate value. A first transmittance ratio, which is a ratio of a first transmittance and a second transmittance that is the transmittance of the second infrared ray between the object and the first and second detectors, Calculated as the characteristic value,
In the third step, the first transmittance using a root including an extinction coefficient ratio that is a ratio of the first extinction coefficient of the first infrared ray and the second extinction coefficient of the second infrared ray. The infrared detection method according to claim 17 or 18, wherein a square root of the ratio is calculated to calculate a first calculated temperature, and the calculated first calculated temperature is calculated as the temperature of the object. The infrared detection method according to claim 19, wherein, in the third step, the first calculated temperature calculated by the following equation (1) is calculated as the temperature of the object.

[In the formula (1), h is Planck's constant, k is Boltzmann's constant, c is the speed of light, λ ₂ is the first wavelength, and λ ₃ is the second wavelength. Is a wavelength, α is a ratio of the spectral radiance emitted by the object detected by the first and second detectors, T _est1 is the first calculated temperature, and ε _a (Λ ₂ ) is the first extinction coefficient, ε _a (λ ₃ ) is the second extinction coefficient, and I(λ ₂ , T) is the first spectral irradiance. , I(λ ₃ , T) is the second spectral irradiance, R _est is the approximate value, and T is the absolute temperature. ] The infrared detection method according to claim 19 or 20, wherein, in the third step, a second calculated temperature obtained by correcting the first calculated temperature is calculated as the temperature of the object. 22. The infrared detection method according to claim 21, wherein in the third step, a second calculated temperature corrected by the following equation (2) is calculated as the temperature of the object.

[In Formula (2), h is Planck's constant, k is Boltzmann's constant, c is the speed of light, λ ₂ is the first wavelength, and λ ₃ is the second wavelength. Wavelength, T _est1 is the first calculated temperature, T _est2 is the second calculated temperature, ε _a (λ ₂ ) is the first extinction coefficient, and ε _a ( λ ₃ ) is the second extinction coefficient, R _est is the approximate value, and R(T _est1 ) is the black body spectral radiance at the first calculated temperature and the first wavelength. , The ratio of the first calculated temperature and the blackbody spectral radiance at the second wavelength. ] In the first step, further detecting a third spectral irradiance of a third infrared having a third wavelength shorter than the first wavelength,
In the second step, a third transmittance, which is one of the first and second transmittances, is calculated from the first transmittance ratio, and the first transmittance is calculated from the object. , A fourth transmittance, which is the transmittance of the third infrared ray between the second and third detectors, is calculated from the third transmittance,
20. The infrared detection method according to claim 19, wherein in the third step, the temperature of the object is calculated based on the calculated fourth transmittance and the third transmittance. 24. The method according to claim 17, further comprising a fifth step of calculating an absolute amount or concentration of an absorber existing between the object and the first and second detectors based on the characteristic value. The infrared detection method according to any one of 1. In the second step, based on the first spectral irradiance ratio and the approximate value, a ratio of a first emissivity at the first wavelength and a second emissivity at the second wavelength. Calculate a certain emissivity ratio as the characteristic value,
The infrared detection method according to claim 17, wherein in the third step, the temperature of the object is calculated based on the calculated emissivity ratio. In the second step, a third emissivity that is an emissivity of either one of the first and second emissivity is calculated based on the emissivity ratio,
The infrared detection method according to claim 25, wherein in the third step, the temperature of the object is calculated based on the calculated third emissivity. Further comprising a sixth step of selecting the first and second wavelengths in the wavelength range from mid infrared to far infrared.
In the sixth step, the error between the temperature of the object and the calculated temperature of the object in the measurement range of the temperature of the object is smaller than the accuracy rating that defines the accuracy of the calculated temperature. The infrared detection method according to any one of claims 17 to 26, wherein the first and second wavelengths are selected as described above. The first detector for detecting the first spectral irradiance and the second detector for detecting the second spectral irradiance are the same detector of quantum well type or quantum dot type,
The infrared detection method further comprises a seventh step of applying a voltage to the same detector to control the wavelengths detected by the first and second detectors to the first and second wavelengths, respectively. The infrared detection method according to any one of claims 17 to 22. The first detector that detects the first spectral irradiance, the second detector that detects the second spectral irradiance, and the third detector that detects the third spectral irradiance are quantum It consists of the same detector of the well type or quantum dot type,
The infrared detection method further comprises an eighth step of applying a voltage to the same detector to control the wavelengths detected by the first to third detectors to the first to third wavelengths, respectively. The infrared detection method according to any one of claims 23 to 27. The first detector for detecting the first spectral irradiance and the second detector for detecting the second spectral irradiance constitute a detector group arranged in an array,
In the first step, each of the plurality of detector groups detects the first and second spectral irradiances,
In the second step, a process of calculating the characteristic value based on the first spectral irradiance ratio and the approximate value is executed for a plurality of sets of the first and second spectral irradiances and the plurality of the Calculate the characteristic value,
In the third step, a plurality of temperatures in a plurality of regions of the target object are calculated based on the plurality of characteristic values, and a temperature distribution of the target object is calculated based on the calculated plurality of temperatures. Item 18. The infrared detection method according to Item 17. The first detector that detects the first spectral irradiance, the second detector that detects the second spectral irradiance, and the third detector that detects the third spectral irradiance are arrays. Form a detector group arranged in a
In the first step, each of the plurality of detector groups detects the first to third spectral irradiances,
In the second step, a process of calculating the third transmittance from the first transmittance ratio is performed on a plurality of sets of the first and second spectral irradiances detected by the plurality of detector groups. Executing to calculate a plurality of third transmittances, calculating a plurality of the fourth transmittances from the plurality of third transmittances,
In the third step, a plurality of temperatures in a plurality of regions of the object are calculated based on the plurality of third transmittances and the plurality of fourth transmittances, and based on the calculated plurality of temperatures. 24. The infrared detection method according to claim 23, wherein the temperature distribution of the object is calculated by calculating the temperature distribution. The reception means sets the first spectral irradiance of the first infrared ray having the first wavelength and the second spectral irradiance of the second infrared ray having the second wavelength longer than the first wavelength. The first step of accepting,
The calculating means has a first spectral irradiance ratio, which is a ratio of the first spectral irradiance and the second spectral irradiance, a blackbody spectral radiance at the first wavelength, and the second wavelength. A second step of calculating a characteristic value of the spectral radiance at the first and second wavelengths based on an approximate value of the ratio to the black body spectral radiance at
A program for causing a computer to execute a third step of calculating the temperature of an object based on the calculated characteristic value of the calculated spectral radiance. The program for causing a computer to execute according to claim 32, wherein the first and second wavelengths are longer than a peak wavelength at which a maximum value of black body spectral radiance is obtained. A computer-readable recording medium in which the program according to claim 32 or 33 is recorded.

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