JP6392673B2 - Hygrometer and humidity measurement method - Google Patents

Description

  The present invention relates to a measurement technique, and relates to a hygrometer and a humidity measurement method.

  As the hygrometer, there are a moisture meter, a polymer capacitive hygrometer, a near-infrared spectroscopic hygrometer, and the like (for example, see Patent Document 1). The wet / dry meter includes a dry bulb thermometer and a wet bulb thermometer. In the wet bulb thermometer, when water evaporates from the wet bulb, the wet bulb is cooled by the heat of vaporization. Therefore, a temperature difference is generated between the dry bulb thermometer and the wet bulb thermometer depending on the degree of air drying. Therefore, it is possible to obtain the humidity from the temperature difference between the dry bulb thermometer and the wet bulb thermometer.

  The polymer capacitive hygrometer includes a lower electrode, a moisture-sensitive polymer disposed on the lower electrode, and a moisture-permeable upper electrode disposed on the moisture-sensitive polymer. In the polymer capacitive hygrometer, moisture contained in the measurement air passes through the moisture-permeable upper electrode and is adsorbed by the moisture-sensitive polymer. Humidity is measured by measuring the dielectric constant of the moisture-sensitive polymer thus changed by changing the capacitance between the upper and lower electrodes.

  The near-infrared spectroscopic hygrometer includes a standard cell that contains air with a known amount of water vapor, and a measurement unit that measures the absorbance by irradiating near-infrared rays in the standard cell. The near-infrared spectroscopic hygrometer obtains the humidity of the outside air using a calibration curve with the measured absorbance in the standard cell as a reference value.

JP-A-8-254580

  The present inventors have found that the conventional hygrometer has no heat resistance, and there is a problem that optical parts and electrical parts are easily broken by moisture. Furthermore, the present inventors conventionally have a hygrometer that draws air to be measured into the cell and measures the humidity. However, when the air to be measured is drawn into the cell, the temperature decreases and condensation occurs, resulting in optical It has been found that there is a problem that scatter occurs and the relative humidity changes. Accordingly, an object of the present invention is to provide a hygrometer and a humidity measuring method capable of measuring humidity regardless of temperature.

  Aspects of the present invention include: (a) a heat-resistant inspection tube provided with a heat-resistant window; and (b) an inspection light having at least a wavelength absorbed by water toward the inside of the inspection tube through the window. (C) a light receiver that receives the inspection light transmitted through the inside of the inspection tube through the window, and (d) the inside of the inspection tube based on the intensity of the inspection light received by the light receiver. The gist of the present invention is a hygrometer comprising a humidity specifying unit that specifies the humidity of the water.

  The hygrometer may further include a relationship storage device that stores a relationship between the intensity of the inspection light transmitted through the inside of the inspection tube and the humidity inside the inspection tube. The humidity specifying unit may specify the humidity value inside the test tube based on the intensity value of the inspection light received by the light receiver and the relationship. The relationship may be based on the absorbance inside the test tube when the relative humidity inside the test tube is 100%. The humidity identification unit identifies the humidity value inside the test tube based on the relationship between the intensity value of the inspection light before passing through the inside of the test tube and the intensity value of the inspection light received by the optical receiver. May be.

  In the hygrometer described above, the humidity may be represented by relative humidity, may be represented by specific humidity, or may be represented by a mole fraction.

  The hygrometer may further include a dryness specifying unit that specifies the dryness inside the test tube based on the intensity of the test light received by the light receiver.

  In the hygrometer described above, the inspection light emitter and the light receiver may be connected to the window of the inspection tube via the optical waveguide.

  The hygrometer further includes a reference light emitter that emits reference light in a wavelength band that is less likely to be absorbed by water than the inspection light toward the inside of the inspection tube through the window. And receiving the inspection light and the reference light transmitted through the inside of the inspection tube, and the humidity specifying unit may correct the intensity of the inspection light received by the light receiver based on the intensity of the reference light received by the light receiver. .

  Moreover, the aspect of this invention is (a) irradiating the inside of the heat resistant test | inspection tube provided with the heat resistant window with the test | inspection light which has at least the wavelength absorbed by water through a window; (B) receiving inspection light inside the inspection tube that has passed through the inspection tube through the window; (c) identifying the humidity inside the inspection tube based on the intensity of the received inspection light; The gist is that it is a method for measuring humidity, including

  The humidity measuring method may further include preparing a relationship between the intensity of the inspection light transmitted through the inside of the inspection tube and the humidity inside the inspection tube. The humidity value inside the test tube may be specified based on the intensity value and relationship of the received inspection light. The relationship may be based on the absorbance inside the test tube when the relative humidity inside the test tube is 100%. The humidity value inside the inspection tube may be specified based on the intensity value of the inspection light before passing through the inside of the inspection tube, the intensity value of the received inspection light, and the relationship.

  In the humidity measurement method described above, the humidity may be represented by relative humidity, may be represented by specific humidity, or may be represented by a mole fraction.

  The humidity measuring method may further include specifying the dryness inside the test tube based on the intensity of the received test light.

  In the humidity measuring method, the inspection light emitter that emits inspection light and the light receiver that receives the inspection light may be connected to the window of the inspection tube via an optical fiber.

  The method for measuring humidity further includes emitting reference light having a wavelength band that is less likely to be absorbed by water than the inspection light toward the inside of the inspection tube through the window. The method may further include receiving inspection light and reference light transmitted through the inside, and correcting the intensity of the received inspection light based on the intensity of the received reference light.

  According to the present invention, it is possible to provide a hygrometer and a humidity measuring method capable of measuring humidity regardless of temperature.

It is a schematic diagram of the hygrometer which concerns on the 1st Embodiment of this invention. It is a schematic diagram of the hygrometer which concerns on the 2nd Embodiment of this invention. It is a schematic diagram of the hygrometer which concerns on the 3rd Embodiment of this invention. It is a graph which shows the state change of the water in the standard atmospheric pressure which concerns on the 3rd Embodiment of this invention. It is a graph which shows the absorption spectrum of the saturated vapor | steam and saturated liquid which concern on the 3rd Embodiment of this invention. It is a graph which shows the absorption spectrum of the saturated vapor | steam and saturated liquid which concern on the 3rd Embodiment of this invention, and the relationship of dryness. It is a graph which shows the absorption spectrum of the saturated vapor | steam and saturated liquid which concern on the 3rd Embodiment of this invention, and the relationship of dryness.

  Embodiments of the present invention will be described below. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic. Therefore, specific dimensions and the like should be determined in light of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(First embodiment)
As shown in FIG. 1, the hygrometer according to the first embodiment of the present invention includes a heat-resistant inspection tube 21 provided with heat-resistant windows 121A and 121B, and a inspection tube 21 through the window 121A. An inspection light emitter 11 that emits inspection light having at least a wavelength absorbed by water toward the inside, a light receiver 12 that receives inspection light that has passed through the inside of the inspection tube 21 through the window 121B, and light reception And a humidity specifying unit 301 for specifying the humidity inside the test tube based on the intensity of the test light received by the device 12. Here, heat resistance means, for example, enduring heat of at least 100 ° C. under standard atmospheric pressure.

  For example, air flows inside the inspection tube 21. The inspection tube 21 is connected to a pipe through which air for humidity measurement flows, and it is not necessary to lower the temperature of the air in the pipe in the inspection tube 21. Therefore, the air to be inspected is guided into the inspection tube 21 without lowering the temperature. The window 121A provided in the inspection tube 21 and the window 121B are opposed to each other. The windows 121A and 121B are made of heat resistant glass, for example. The heat resistant test tube 21 provided with the windows 121A and 121B is, for example, a sight glass.

  As the inspection light emitter 11, a light emitting diode (LED) or the like can be used. The wavelength absorbed by water at least in the inspection light is, for example, 1700 nm to 2200 nm. The inspection light may be, for example, near infrared light having a wavelength region of 800 to 2500 nm.

  Connected to the inspection light emitter 11 is an optical waveguide 31 that propagates inspection light to the outer surface of the window 121 </ b> A of the inspection tube 21. A collimator lens may be disposed between the end of the optical waveguide 31 that emits inspection light and the outer surface of the window 121A. For the optical waveguide 31, a plastic optical fiber made of polymethyl methacrylate resin (PMMA: Poly (methymethacrylate)), a glass optical fiber made of quartz glass, or the like can be used, but the inspection light emitter 11 emits. It is not limited to these as long as the inspection light can propagate.

  The inspection light emitted from the inspection light emitter 11 and having at least a wavelength absorbed by water is absorbed inside the inspection tube 21 by water vapor contained in the air. Therefore, when the humidity of air is high, the degree of absorption of inspection light by air tends to be high, and when the humidity of air is low, the degree of absorption of inspection light by air tends to be low.

  An optical waveguide 32 into which inspection light that has passed through the inside of the inspection tube 21 enters is connected to the outer surface of the window 121 </ b> B of the inspection tube 21. The end portion of the optical waveguide 32 faces the end portion of the optical waveguide 31. A lens that allows the inspection light to enter the optical waveguide 32 may be disposed between the outer surface of the window 121 </ b> B and the end of the optical waveguide 32. The optical waveguide 32 guides the inspection light transmitted through the air inside the inspection tube 21 to the light receiver 12. A light intensity detection element such as a photodiode can be used for the light receiver 12.

Here, the humidity of the air in the test tube 21 correlates with the absorbance of the air in the test tube 21. The absorbance of the air in the test tube 21 passed through the air in the test tube 21 relative to the light intensity I ₀ of the test light before passing through the air in the test tube 21 as given by the following equation (1). It is given by the logarithm of the ratio of the light intensity I ₁ of the later inspection light.
A = -ln (I ₁ / I ₀ ) (1)

For example, when the light intensity of the inspection light after humidity has passed through the 100% of the air in the test tube 21 is I ₁ _ _100, humidity y of the air in the test tube 21 and the light reception intensity x of the light receiver 12 Is given by the following equation (2). The relationship given by the following equation (2) is based on the absorbance of air when the relative humidity of air is 100%.
y / 100 = {- ln ( x / I 0)} / {- ln (I 1 _ 100 / I 0)} (2)

The value of the light intensity I ₀ of the inspection light before passing through the air in the inspection tube 21 and the value of the light intensity I _{1 — 100} of the inspection light after passing through the air whose relative humidity in the inspection tube 21 is 100%. Can be obtained in advance as a constant. Therefore, if the value of the light intensity x of the inspection light after the air to be measured whose humidity is unknown is flowed into the inspection tube 21 and the light in the inspection tube 21 is transmitted by the light receiver 12, the above (2). The value of the relative humidity y of the air to be measured can be calculated from the equation.

  A central processing unit (CPU) 300 is connected to the light receiver 12. A related storage device 400 is connected to the CPU 300. The relationship storage device 400 stores, for example, the relationship between the light intensity x of the inspection light transmitted through the air in the inspection tube 21 and the humidity y of the air in the inspection tube 21 as in the above equation (2). . The absorbance in the test tube 21 also depends on the diameter of the test tube 21. Therefore, it is preferable that the diameter of the test tube 21 at the time of humidity measurement is the same as the diameter of the test tube 21 when the relationship is acquired.

  The humidity specifying unit 301 is included in the CPU 300. For example, the humidity specifying unit 301 specifies the value of the relative humidity of the air in the test tube 21 based on the light intensity value of the inspection light received by the light receiver 12 and the relationship given by the above equation (2). To do. For example, the humidity specifying unit 301 receives from the light receiver 12 a measurement value of the received light intensity of the inspection light transmitted through the air inside the inspection tube 21. Further, the humidity specifying unit 301 reads the expression (2) from the relation storage device 400 and substitutes the measured value of the received light intensity into the variable x of the light intensity of the inspection light after passing through the air included in the expression (2). Then, the relative humidity of the air inside the test tube 21 is calculated.

  An input device 321, an output device 322, a program storage device 323, and a temporary storage device 324 are further connected to the CPU 300. As the input device 321, a switch, a keyboard, and the like can be used. The relational expression stored in the relation storage device 400 is input using the input device 321, for example. As the output device 322, an optical indicator, a digital indicator, a liquid crystal display device, or the like can be used. For example, the output device 322 outputs the value of the relative humidity of the air inside the test tube 21 specified by the humidity specifying unit 301. The program storage device 323 stores a program for causing the CPU 300 to execute data transmission / reception between devices connected to the CPU 300. The temporary storage device 324 temporarily stores data in the calculation process of the CPU 300.

  According to the hygrometer according to the first embodiment described above, it is possible to measure the humidity of high-temperature air that includes, for example, wet steam and superheated steam.

(Second Embodiment)
As shown in FIG. 2, the hygrometer according to the second embodiment refers to a wavelength band that is less likely to be absorbed by water than the inspection light toward the air inside the inspection tube 21 through the window 121 </ b> A. A reference light emitter 111 that emits light is further provided. In the second embodiment, the light receiver 12 receives the inspection light and the reference light transmitted through the air inside the inspection tube 21 through the window 121B. Further, the humidity specifying unit 301 corrects the intensity of the inspection light received by the light receiver 12 based on the intensity of the reference light received by the light receiver 12.

  The wavelength band that is hardly absorbed by water is, for example, less than 1300 nm. For the reference light emitter 111, a light emitting diode or the like can be used.

  An optical waveguide 30 that propagates inspection light is connected to the inspection light emitter 11, and an optical waveguide 130 that propagates reference light is connected to the reference light emitter 111. The multiplexer 14 is connected to the optical waveguide 30 and the optical waveguide 130. Connected to the multiplexer 14 is an optical waveguide 31 that propagates the inspection light and the reference light combined by the multiplexer 14 to the outer surface of the window 121 </ b> A of the inspection tube 21.

  A part of the inspection light and the reference light can be reflected, scattered, refracted, etc. inside the inspection tube 21. The loss of inspection light due to reflection, scattering, refraction, and dirt on the windows 121A and 121B is substantially the same as the loss of reference light.

In the second embodiment, the optical waveguide 32 guides the inspection light and the reference light transmitted through the air inside the inspection tube 21 and the window 121 </ b> B to the light receiver 12. In the second embodiment, the humidity specifying unit 301 subtracts the absorbance of the air with respect to the reference light from the absorbance A of the air with respect to the inspection light given by the above formula (1), for example, according to the following formula (3): reflection inside the test tube 21, and calculates the scattering and refraction, etc., as well as a window 121A, the corrected absorbance a _C obtained by correcting the loss of the inspection light due to contamination or the like of 121B.
A _C = A-(-ln (I _ref1 / I _ref0 )) (3)
I _ref0 represents the light intensity of the reference light before passing through the window 121A and the air, and I _ref1 represents the light intensity of the reference light after passing through the air and the windows 121A and 121B. For the light intensity of the reference light before passing through the window 121A and the air, a value measured in advance may be used as a constant.

  In the second embodiment, for example, the humidity specifying unit 301 substitutes the corrected absorbance when the relative humidity of the air is 100% into the denominator of the right side of the above equation (2), and the test is performed on the numerator of the right side. By substituting the corrected absorbance of the air to be measured in the tube 21, the relative humidity of the air to be measured is calculated.

  Other components of the hygrometer according to the second embodiment are the same as those of the hygrometer according to the first embodiment. According to the hygrometer according to the second embodiment, the humidity of the air in the test tube 21 can be specified more accurately.

(Third embodiment)
As shown in FIG. 3, the hygrometer according to the third embodiment further includes a dryness specifying unit 302 that specifies the dryness inside the test tube 21 based on the intensity of the test light received by the light receiver 12. .

For example, wet steam (a mixture of saturated steam and saturated liquid) can pass through the test tube 21. As shown in FIG. 4, under standard atmospheric pressure, water reaches a boiling point (100 ° C.), and then water as droplets and steam are mixed to become wet steam in a coexisting state. When the pressure is constant, since the latent heat of wet steam changes due to heating and cooling, the saturation temperature is constant. Here, as given by the following equation (4), the mass ratio of saturated steam to the total amount of wet steam is referred to as “dryness”. Therefore, the dryness of the saturated steam is 1, and the dryness of the saturated liquid is 0.
z = m _vapor / (m _vapor + m _water ) (4)
z represents the degree of dryness, m _vapor represents the mass of saturated vapor, and m _water represents the mass of saturated liquid.

  When the dryness is 1, the relative humidity of the wet steam is 100%. When the dryness is less than 1, the relative humidity of the wet steam is greater than 100%. In the superheated steam state, the relative humidity of the wet steam is less than 100%.

Here, the mass of the saturated vapor is proportional to the absorbance of the saturated vapor. Further, the mass of the saturated liquid is proportional to the absorbance of the saturated liquid. Therefore, the following expression (5) is derived from the above expression (4).
z = m _vapor / (m _vapor + m _water )
= a _vapor / (a _vapor + k × a _water ) (5)
a _vapor represents the absorbance of the saturated vapor, a _water represents the absorbance of the saturated liquid, and k represents the molar extinction coefficient ratio given by the following equation (6).
k = e _vapor / e _water (6)
e _vapor represents the extinction coefficient of saturated vapor, and e _water represents the extinction coefficient of saturated liquid.

Absorbance A _s of wet steam, as given by the following equation (7), and the absorbance of the saturated vapor, and the absorbance of the saturated liquid, is given by the sum of.
A _s = a _vapor + a _water (7)
Further, the absorbance of the wet steam is given by the logarithm of the ratio of the light intensity of the light after passing through the wet steam to the light intensity of the light before passing through the wet steam as given by the following equation (8). .
A _s = -ln (I _steam1 / I _steam0 ) (8)
I _steam0 represents the light intensity before passing through the wet steam, and I _steam1 represents the light intensity after passing through the wet steam.

As shown in FIG. 5, the absorption spectra of the saturated vapor and the saturated liquid are different, and when the dryness changes, the absorption spectrum of the saturated liquid changes. For example, since the dryness degree is decreased content of saturated liquid in the wet steam as it changes direction from 0 to 1, as shown in FIG. 6, also the absorbance A _s of wet steam at the peak wavelength of the absorption spectrum of the saturated liquid Decrease. The wavelength at the peak of the absorption spectrum of the saturated liquid is around 1880 nm. In wet steam, since the volume of saturated steam is much larger than the volume of saturated liquid, the absorbance of saturated steam can be regarded as constant if the pressure is constant.

The dryness of the wet steam is also given by the following formula (9) derived from the above formulas (5), (7) and (8).
z = 1 / (1-k + (k / a _vapor ) × A _S ) (9)
The molar extinction coefficient ratio k is a constant. As described above, the absorbance a _Vapor saturated steam can be considered a constant under constant pressure, the absorbance a _Vapor saturated steam can be derived from the pressure of the wet steam. Therefore, by measuring the absorbance A _S of wet steam, it is possible to calculate the dryness fraction z of wet steam from (9).

  In the third embodiment, the inspection light emitter 11 shown in FIG. 3 emits inspection light including a wavelength band that is absorbed by the saturated solution. The inspection light is, for example, near infrared light having a wavelength region of 800 to 2500 nm. As shown in FIG. 7, the inspection light may have the peak wavelength of the absorption spectrum of the saturated liquid as the center wavelength. In the wavelength region, the absorption spectra of the saturated vapor and the saturated liquid overlap.

  In the third embodiment, as shown in FIG. 7, the reference light emitter 111 shown in FIG. 3 emits reference light in a wavelength band that is difficult to be absorbed by wet steam over the entire range of dryness. The wavelength band that is difficult to be absorbed by wet steam is, for example, less than 1300 nm.

  The inspection light emitted from the inspection light emitter 11 shown in FIG. 3 is absorbed by the saturated liquid contained in the wet steam inside the inspection tube 21. As described above, the saturated liquid contained in the wet steam decreases as the dryness approaches from 0 to 1. Therefore, as the dryness of the wet steam in the test tube 21 approaches 0 to 1, the absorbance of the wet steam tends to decrease.

  The hygrometer according to the third embodiment may further include a pressure sensor 13 that measures the pressure of the wet steam in the test tube 21. The pressure sensor 13 is connected to the CPU 300. However, the pressure information may be obtained from upstream or downstream of the inspection tube 21.

  In the third embodiment, the relation storage device 400 further stores a relational expression between the absorbance of the wet steam and the dryness of the wet steam, for example, the above formula (9).

  In the third embodiment, the humidity specifying unit 301 included in the CPU 300 specifies the humidity inside the test tube 21 as in the first or second embodiment.

  The dryness specifying unit 302 included in the CPU 300 receives from the light receiver 12 measurement values of the received light intensity of the inspection light and the reference light transmitted through the wet steam inside the inspection tube 21. Further, the dryness specifying unit 302 receives the measured value of the pressure of the wet steam in the test tube 21 from the pressure sensor 13.

Dryness of specifying unit 302, based on the inspection light intensity I _Steam1 the light receiver 12 has received, for example, according to the above (8), identifies the absorbance A _S of wet steam in the test tube 21. Note that the light intensity I _steam0 of the inspection light before passing through the wet steam may use a value measured in advance as a constant.

Further, the dryness specifying unit 302 subtracts the absorbance of the reference light from the absorbance of the inspection light according to, for example, the following equation (10), and reflects, scatters, and refractions inside the inspection tube 21 and stains of the windows 121A and 121B. The corrected absorbance A _SC is calculated by correcting the loss of the inspection light due to.
A _SC = A _S -(-ln (I _ref1 / I _ref0 ) (10)
I _ref0 represents the light intensity of the reference light before passing through the wet steam, and I _ref1 represents the light intensity of the reference light after passing through the wet steam. A value measured in advance may be used as a constant for the light intensity of the reference light before passing through the wet steam.

Further, the dryness specifying unit 302 calculates the absorbance a _vapor of saturated vapor depending on the pressure based on the measured value of the pressure of the wet steam in the test tube 21 received from the pressure sensor 13. Further, the dryness specifying unit 302 substitutes, for example, the value of the corrected absorbance A _SC of the wet vapor inside the test tube 21 and the value of the absorbance a _vapor of the saturated vapor into the above equation (9), The dryness z of the wet steam in the inspection tube 21 is calculated. However, if the pressure is constant, the absorbance a _vapor of the saturated vapor can be regarded as constant. Therefore, if the pressure in the test tube 21 is constant, a constant may be used for the absorbance a _vapor of the saturated vapor. In this case, the hygrometer according to the third embodiment may not include the pressure sensor 13.

  In the third embodiment, the output device 322 further outputs the dryness value of the wet steam inside the test tube 21 specified by the dryness specifying unit 302.

  Other components of the hygrometer according to the third embodiment are the same as those of the hygrometer according to the second embodiment. According to the hygrometer according to the third embodiment described above, not only the humidity inside the test tube 21 but also the dryness can be measured.

(Other embodiments)
Although the present invention has been described by the embodiments as described above, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques should be apparent to those skilled in the art. For example, the humidity measured by the hygrometer may be represented by specific humidity or may be represented by a mole fraction. In addition, the relationship between the received light intensity by the light receiver and the humidity may be acquired in advance by measuring the humidity of the air using a conventional humidity measuring method and measuring the intensity of the inspection light that has passed through the air. Good. Conventionally, there are various humidity measurement methods, but when acquiring the relationship, any one of them may be used alone or in combination. Note that the relationship between the intensity of light received by the light receiver and the humidity may be stored as a table.

  Furthermore, in the third embodiment, the relationship between the intensity of light received by the light receiver and the dryness of the wet steam is determined by the conventional dryness measurement method while heating the wet steam with a boiler or the like. And may be acquired in advance by measuring the intensity of the inspection light transmitted through the wet steam. Conventionally, there are various dryness measurement methods, but when acquiring the relationship, any one of them may be used alone or in combination. In addition, the relationship between the light reception intensity by the light receiver and the dryness of the wet steam may be stored as a table. Thus, it should be understood that the present invention includes various embodiments and the like not described herein.

  Although the hygrometer according to the embodiment of the present invention is not limited to the following, humidity measurement in a high-temperature environment, humidity measurement in a cooking oven or heating facility having a function of supplying steam into the chamber, humidity in the drying furnace Measurement, visualization of latent heat increase effect by pressure reducing valve, dryness measurement to obtain optimum boiler efficiency, moisture loss measurement of steam turbine, optimal dryness control of heat effector, control of food manufacturing process such as steaming process of noodles, And can be used for controlling chemical processes.

DESCRIPTION OF SYMBOLS 11 Inspection light emitter 12 Light receiver 13 Pressure sensor 14 Combiner 21 Inspection tube 30, 31, 32, 130 Optical waveguide 111 Reference light emitter 121A, 121B Window 300 Central processing unit 301 Humidity specific part 302 Dryness specific part 321 Input device 322 Output device 323 Program storage device 324 Temporary storage device 400 Relational storage device

Claims (10)

A heat-resistant test tube with a heat-resistant window;
An inspection light emitter that emits inspection light having at least a wavelength absorbed by water toward the inside of the inspection tube through the window;
A light receiver for receiving the inspection light transmitted through the inspection tube through the window;
A relationship storage device that stores the relationship between the intensity of inspection light transmitted through the inside of the inspection tube and the relative humidity inside the inspection tube;
Based on the intensity value of the inspection light received by the light receiver and the relationship, a humidity specifying unit that specifies the relative humidity inside the inspection tube,
With
The relationship is based on the absorbance inside the test tube when the relative humidity inside the test tube is 100%.
Hygrometer. Based on the relationship between the humidity specifying unit, the intensity value of the inspection light before passing through the inside of the inspection tube, the intensity value of the inspection light received by the light receiver, and the relationship, The hygrometer according to claim 1 , wherein a relative humidity value is specified. The hygrometer according to claim 1 or 2 , further comprising a dryness specifying unit that specifies the dryness inside the test tube based on the intensity of the inspection light received by the light receiver. The hygrometer according to any one of claims 1 to 3 , wherein the inspection light emitter and the light receiver are connected to a window of the inspection tube via an optical waveguide. A reference light emitter that emits reference light in a wavelength band that is less likely to be absorbed by water compared to the inspection light toward the inside of the inspection tube through the window,
The light receiver receives the inspection light and the reference light transmitted through the inspection tube through the window,
The humidity specifying unit corrects the intensity of the inspection light received by the light receiver based on the intensity of the reference light received by the light receiver.
The hygrometer according to any one of claims 1 to 4 . Irradiating inspection light having at least a wavelength absorbed by water through the window toward the inside of the heat-resistant inspection tube provided with the heat-resistant window;
Receiving the inspection light transmitted through the inspection tube through the window;
Preparing a relationship between the intensity of inspection light transmitted through the inside of the inspection tube and the relative humidity inside the inspection tube;
Identifying the relative humidity inside the test tube based on the intensity value of the received test light and the relationship ;
Only including,
The relationship is based on the absorbance inside the test tube when the relative humidity inside the test tube is 100%.
How to measure humidity. The relative humidity value inside the inspection tube is specified based on the intensity value of the inspection light before passing through the inside of the inspection tube, the intensity value of the received inspection light, and the relationship. Item 7. The humidity measuring method according to Item 6 . The humidity measuring method according to claim 6 or 7 , further comprising specifying a dryness inside the inspection tube based on the intensity of the received inspection light. And inspection light emitter for emitting the inspection light, a light receiver for receiving the inspection light, but is connected to the window of the test tube via an optical waveguide, to any one of claims 6 to 8 The humidity measurement method described. Further including emitting reference light in a wavelength band that is less likely to be absorbed by water than the inspection light toward the inside of the inspection tube through the window;
Receiving the inspection light and the reference light transmitted through the inspection tube through the window;
Correcting the intensity of the received inspection light based on the intensity of the received reference light;
The humidity measuring method according to any one of claims 6 to 9 .