JP4586650B2 - Temperature measurement module and temperature measurement method using the same - Google Patents

Description

  The present invention relates to a temperature measurement module, for example, a temperature measurement module that measures the temperature of a pan or the like heated by a gas stove or electromagnetic stove in a non-contact manner, and a temperature measurement method using the same.

  Generally, methods for measuring the temperature of a pan heated with a stove or the like in a non-contact manner include a radiation intensity measurement method and a two-color measurement method. The radiation intensity measurement method focuses on the fact that the output of the infrared detection means depends on the emissivity of the object to be measured, and detects the pan temperature using the known emissivity and the measured radiation intensity. It is.

On the other hand, the two-color measurement method is a method that does not depend on emissivity, and is a method of measuring the infrared intensity in two wavelength regions and calculating and detecting the temperature according to a certain functional relationship based on the ratio of the infrared intensity ( According to this method, according to this method, it is said that the temperature of any pan of an alumite pan and a glass pan can be measured.
Note that the temperature of a pan or the like that the present invention is mainly intended to solve is 300 ° C. or less, and the radiation emitted from the object to be measured in that temperature band is mainly in the infrared region. Therefore, in this invention, the radiation radiated | emitted from a to-be-measured object is described as infrared rays.
JP 2002-340339 A

  However, the former radiation intensity measurement method is easily affected by emissivity, and the emissivity varies greatly depending on the material of the pan. For this reason, if the emissivity is fixed to a specific numerical value, the variation in the detected temperature increases depending on the material of the pan. As a result, it is necessary to input an emissivity corresponding to the material of the pan every time the material of the pan changes, which is not practical because it is complicated.

  On the other hand, the emissivity spectrum indicating the emissivity for each wavelength is unique to the object to be measured, and may vary greatly depending on the material of the pan. For this reason, there is a problem that the temperature of the pans of different materials cannot be accurately detected only by measuring two specific wavelength ranges as in the two-color measurement method.

  In view of the above problems, the present invention provides a temperature measurement module capable of accurately measuring a temperature in a non-contact manner even if the material of an object to be measured such as a pan is different, and a temperature measurement method using the same. And

  In order to solve the above-described problem, the temperature measurement module according to the present invention includes a first infrared detection unit that measures a specific wavelength range of infrared rays emitted from the measurement target, and a wavelength range that is measured by the first infrared detection unit. Second infrared detecting means for measuring a longer wavelength range, and a first temperature for detecting the temperature of the object to be measured based on the ratio of the infrared intensity measured by the first infrared detecting means and the second infrared detecting means. The detection means, the second temperature detection means for detecting the temperature of the object to be measured based on the infrared intensity measured by the second infrared detection means, the first temperature detection means and the second temperature detection means output Comparing means for comparing temperature data and outputting higher temperature data is provided.

According to the present invention, when the emissivity is low, such as an object to be measured having a metallic glossy surface, without using a temperature detection method based on infrared intensity that outputs temperature data lower than the actual temperature, High temperature data detected based on the ratio of the infrared intensity in the two wavelength regions is selected.
On the other hand, when the infrared intensity in the short wavelength region is not large like the object to be measured having a non-metallic glossy surface, the infrared intensity ratio of the two wavelength regions that outputs temperature data lower than the actual temperature is set. The temperature data detected based on the infrared intensity in the long wavelength range where a stable and large emissivity can be obtained without using the temperature detection method based on the temperature is selected.
Therefore, by always selecting and outputting higher temperature data from the two temperature data output by the first and second temperature detection means, a temperature measurement module capable of detecting the temperature more accurately is obtained.

  Other measurement modules according to the present invention include a first infrared detection means for measuring a specific wavelength range of infrared rays emitted from the measurement object, and a wavelength range longer than the wavelength range measured by the first infrared detection means. The second infrared detecting means for measuring the reference temperature detecting means for measuring the ambient temperature of the first and second infrared detecting means, the infrared intensity measured by the first infrared detecting means and the second infrared detecting means. First temperature detecting means for detecting the temperature of the measurement object based on the ratio; second temperature detection means for detecting the temperature of the measurement object based on the infrared intensity measured by the second infrared detection means; A third temperature detecting means for detecting the ambient temperature based on the measurement data of the reference temperature detecting means; a first adding means for adding the temperature data of the first temperature detecting means and the third temperature detecting means; The second adding means for adding the temperature data of the temperature detecting means and the third temperature detecting means and the temperature data output by the first adding means and the second adding means are compared, and a comparison is made to output higher temperature data. It is good also as a structure which consists of a means.

  According to the present invention, in addition to the above-described effects, the temperature can be measured with higher accuracy by adding the ambient temperature.

As an embodiment according to the present invention, the measurement wavelength range of the first infrared detection means may be 3.0 μm to 4.2 μm, and the measurement wavelength range of the second infrared detection means is 8.0 μm to 13 μm. There may be.
According to the present embodiment, in addition to the above-described effects, measurement is performed in a wavelength region called a so-called atmospheric window, so that disturbance due to a gas flame, hot air, or the like can be avoided, and highly accurate temperature measurement is possible.

  In the temperature measuring method according to the present invention, the specific wavelength range of the infrared ray emitted from the object to be measured is measured by the first infrared detecting means, and the wavelength range longer than the wavelength range measured by the first infrared detecting means is selected. After measuring with the second infrared detection means, the first temperature detection means detects the temperature of the object to be measured based on the ratio of the infrared intensity measured by the first infrared detection means and the second infrared detection means, and Based on the infrared intensity measured by the second infrared detecting means, the temperature of the measurement object is detected by the second temperature detecting means, and then the temperature data output by the first temperature detecting means and the second temperature detecting means. Are compared by the comparison means, and higher temperature data is output.

According to the present invention, when the emissivity is low in the entire wavelength range as in the measurement object having a metallic glossy surface, the infrared intensity that causes the output of temperature data lower than the actual temperature is not used. High temperature data detected based on the ratio of the two infrared radiation intensities is selected.
On the other hand, when the emissivity spectrum is characteristic of the material of the object to be measured, such as the object to be measured having a non-metallic glossy surface, and is not stable between the two wavelength ranges, a stable high emissivity is obtained. High temperature data detected based on infrared intensity in a long wavelength range that can be secured is selected.
Therefore, a temperature measurement method capable of detecting the temperature more accurately is obtained by always selecting and outputting higher temperature data from the two temperature data output by the first and second temperature detection means.

  In another temperature measurement method according to the present invention, a specific wavelength range of infrared rays emitted from an object to be measured is measured by first infrared detection means, and a wavelength range longer than the wavelength range measured by the first infrared detection means. Is measured by the second infrared detecting means, and the ambient temperature of the first and second infrared detecting means is measured by the reference temperature detecting means, and then the infrared rays measured by the first infrared detecting means and the second infrared detecting means are measured. The temperature of the object to be measured is detected by the first temperature detecting means based on the intensity ratio, and the temperature of the object to be measured is detected by the second temperature detecting means based on the infrared intensity measured by the second infrared detecting means. In addition, the ambient temperature is detected by the third temperature detecting means based on the measurement data of the reference temperature detecting means, and the temperature data of the first temperature detecting means and the third temperature detecting means is then detected by the first adding means. And the temperature data of the second temperature detection means and the third temperature detection means are added together by the second addition means, and finally, the temperature data output from the first addition means and the second addition means are compared. The comparison means outputs a higher temperature data.

  According to the present invention, in addition to the above-described effects, the temperature can be measured with higher accuracy by adding the ambient temperature.

As an embodiment according to the present invention, the measurement wavelength range of the first infrared detection means may be 3.0 μm to 4.2 μm, and the measurement wavelength range of the second infrared detection means is 8.0 μm to 13 μm. There may be.
According to the present embodiment, in addition to the above-described effects, measurement is performed in a wavelength range called a so-called atmospheric window, so that disturbance due to gas flame, hot air, etc. can be avoided, and highly accurate temperature measurement is possible. .

Embodiments according to the present invention will be described with reference to the accompanying drawings of FIGS.
As shown in FIGS. 1 and 2, the temperature measurement module 10 according to the first embodiment includes a sensor unit 20, an analog circuit unit 30, and a digital circuit unit 40.

  As shown in FIG. 1, the sensor unit 20 includes a first infrared sensor 22, a second infrared sensor 23, and a reference temperature sensor 24 in one housing 21. This is to reduce variations in characteristics between sensors with respect to environmental changes and to reduce manufacturing costs. Examples of the first and second infrared sensors 22 and 23 include a photodiode, a thermopile, and the like. The first and second infrared sensors 22 and 23 themselves receive energy corresponding to the temperature difference between the object to be measured and the first and second infrared sensors 22 and 23 with infrared light, and output a voltage corresponding to the energy. To do.

The first filter 25 is for passing only infrared rays having a wavelength range of 3.0 μm to 4.2 μm, preferably 3.5 μm to 4.0 μm. The first filter 26 passes only infrared rays having a wavelength range of 8.0 μm to 13 μm, preferably 8.0 μm to 12.0 μm. The wavelength range as described above is selected for the following reason.
That is, although the gas flame and H ₂ O and CO ₂ in the hot air located around the gas flame radiate infrared rays, as shown in FIG. 4, a wavelength called a so-called atmospheric window in which radiant energy cannot be detected. There is a zone. Therefore, in order to avoid the influence of disturbance due to gas flame and hot air and improve the measurement accuracy, the wavelength range called the atmospheric window as described above was selected.

  Examples of the first and second filters 25 and 26 include those in which an interference film is formed on the surface of a silicon wafer or quartz by vacuum deposition. Further, a band-pass filter may be formed by forming different interference films on the front and back surfaces of the silicon wafer or the like. Further, a combination of a separate short pass filter and a long pass filter may be used as the band pass filter.

  The reference temperature sensor 24 detects energy corresponding to the temperature of the first and second infrared sensors 22 and 23 themselves, and adds this to the detection results of the first and second infrared sensors 22 and 23, thereby measuring This is for more accurately detecting the temperature of the object. As the reference temperature sensor 24, for example, a thermistor is used.

  The analog circuit section 30 amplifies the signals detected by the first and second infrared sensors 22 and 23 and the reference temperature sensor 24 by amplifiers 31, 32 and 33, respectively, and can adjust the variation in characteristics of each sensor. is there. And by providing the analog switching means 34, the output data for every sensor are individually output to the digital circuit part 40, and the circuit is simplified.

  The digital circuit unit 40 converts the amplified analog signal into a digital signal by the A / D converter 41, and then stores it in a buffer (not shown), from the first and second infrared sensors 22, 23 and the reference sensor 24. When the data are collected, the data stored in the buffer is output to the first, second and third temperature detecting means 42, 43 and 44, respectively. In particular, as shown in FIG. 3, the infrared intensity detected by the first infrared sensor 22 and the second infrared sensor 23 is input to the first temperature detecting means 42, respectively, and the ratio of both infrared intensity and the temperature correlation function (FIG. 8A). ) To calculate the temperature, and output the calculation result to the first adding means.

  As shown in FIG. 3, the second temperature detection means 43 calculates the temperature based on the infrared intensity detected by the second infrared sensor 23 and the temperature correlation function (FIG. 8B), and the calculation result is the second addition means. Output to 46. Further, the third temperature detection means 44 calculates the temperature based on the output of the reference temperature sensor 24 and the temperature correlation function, and outputs the calculation results to the first and second addition means 45 and 46, respectively.

  The first adding means 45 adds the temperature data input from the first temperature detecting means 42 and the third temperature detecting means 44 and outputs the result to the comparing means 47. Similarly, the second addition means 46 adds the temperature data input from the second temperature detection means 43 and the third temperature detection means 44 and outputs the result to the comparison means 47.

  The comparison means 47 compares the temperature data output from the first and second addition means 45 and 46 and outputs higher temperature data as the measured temperature.

The reason why the high temperature data is selected and output from the temperature data output from the first and second addition means 45 and 46 as in the present embodiment is as follows.
That is, when the object to be measured is a metallic gloss surface such as stainless steel or aluminum, the emissivity is very low (see FIG. 5). For example, when the stainless steel is heated at 150 ° C., the emissivity of the stainless steel pan is as low as about 0.1 to 0.2. Therefore, if the temperature is calculated based on the correlation between the infrared intensity and the temperature by the radiation intensity measurement method assuming an emissivity of about 0.85, the temperature is always lower than the temperature at which the stainless steel pan is actually heated. Is output by the second temperature detection means (FIG. 9B).

  On the other hand, the so-called two-color measurement method is a method of processing based on the ratio of the infrared radiation intensity in different wavelength ranges without using the emissivity as a reference. As is clear from FIG. 5, the emissivity of the stainless steel in the wavelength range of 3.0 μm to 4.2 μm and the emissivity of the wavelength range of 8.0 to 13 μm are stable. Furthermore, the emissivity in the wavelength range of 3.0 μm to 4.2 μm is about 1.6 times larger than the emissivity in the wavelength range of 8.0 to 13 μm. For this reason, according to the so-called two-color measurement method, it is possible to obtain temperature data that is close to the actual temperature and always larger than the radiation intensity measurement method (FIG. 9A). As a result, by selecting larger temperature data, the temperature of the stainless steel pan having the metallic gloss surface can be accurately detected.

On the other hand, as shown in FIGS. 6 and 7, a pan having a non-metallic glossy surface such as anodized, enamel, and baked paint 1 and 2 has a large emissivity in a wide wavelength range of 8.0 to 13 μm and is stable. ing. For this reason, if the temperature is detected based on the radiation intensity measurement method from the infrared intensity in the wavelength range of 8.0 to 13 μm, the temperature of the pan having the nonmetallic glossy surface can be accurately detected.
However, in the pan such as alumite, the emissivity in the wavelength range of 3.0 μm to 4.2 μm is equal to or smaller than the emissivity in the wavelength range of 8.0 to 13 μm. For this reason, the temperature of the pan is based on a two-color measurement method that assumes that the emissivity in the wavelength range of 3.0 μm to 4.2 μm is about 1.6 times larger than the emissivity of the wavelength range of 8.0 to 13 μm. Even if detected, temperature data larger than that of the radiation intensity measurement method cannot be obtained.

  Therefore, even if the object to be measured is a pan having a metallic gloss surface such as stainless steel, or a pan having a non-metallic gloss surface such as anodized, the temperatures detected by the first and second temperature detecting means 42 and 43, respectively. If the comparison means 47 selects higher temperature data among the data, a temperature measurement module and a temperature measurement method that can always detect an accurate temperature regardless of the material of the pan can be obtained.

Next, the Example by the temperature measurement module concerning this invention is described.
As a measuring apparatus, as shown in FIGS. 10 and 11, the temperature measuring module 10 according to the present invention is arranged in an open space (not shown) so as to face the center of a sample 50 described later at a distance of 80 mm.

  As shown in FIG. 1, the temperature measurement module 10 includes a bandpass filter 25 having a wavelength range of 3.0 μm to 4.2 μm as a first filter and a bandpass filter having a wavelength range of 8.0 μm to 13.0 μm as a second filter. 26 was used. Further, a saner pile is used for the first and second infrared sensors 22 and 23 and a thermistor is used for the reference temperature sensor 24.

  The sample 50, which is an object to be measured, is a plate-like material cut out from the bottom of various pans to a size of about 80 mm wide and about 80 mm long. The types of pots are stainless steel pot, aluminum pot, enamel pot, baking paint pot 1, anodized pot, baking paint pot 2.

  In particular, the baking finish pan 1 is obtained by applying and baking a paint obtained by adding an inorganic filler and ceramic powder to a silicone resin that is a condensate having a silicon skeleton. In addition, the baking coating pan 2 is one that is baked by applying a pure silicone resin paint.

  The sample 50 is fixed by screws 52 to the surface of a heater block 51 made of an aluminum plate having a width of 150 mm, a length of 150 mm, and a thickness of 3 mm, and is bonded and integrated with an epoxy resin to which a silver filler is added. . The heater block 51 is fixed to the surface of a plate-like heating element 53 made of a stainless steel plate having a width of 150 mm, a length of 150 mm, and a thickness of 3.0 mm with screws 54. Nichrome wire is stretched around the back surface of the plate-shaped heating element 53 so that the temperature is uniformly distributed. A ceramic heater may be substituted for the plate-like heating element 53.

  The sample 50 was heated to temperatures of 100 ° C., 150 ° C., 200 ° C. and 250 ° C., and the infrared radiation intensity was measured and processed by the temperature measurement module 10. The measurement results are shown in the chart of FIG.

As is clear from FIG. 12, in the case of a stainless steel pan and an aluminum pan having a metallic gloss surface, it can be seen that the temperature of the object to be measured corresponds well with the output temperature output from the comparison means.
In addition, even in the case of enamel pans, baking pans 1, anodized pans, and baking pans 2 that do not have a metallic luster surface, the temperature of the object to be measured and the output temperature output from the comparison means correspond well. I understand that.
Therefore, as a result of comparing the temperature of the object to be measured with the output temperature of the comparison means, if the comparison means selects a higher temperature among the first and second temperature detection means after adding the reference temperature, the object to be measured It was confirmed to approximate the temperature of the object.

Note that two addition means are not necessarily provided, and temperature correction may be performed by one addition means.
Further, the temperature correction based on the temperature data of the reference temperature sensor may be performed by adding the temperature data based on the reference temperature sensor in the adding means after the comparing means outputs the temperature data to the adding means.

  The temperature measurement module and the temperature measurement method according to the present invention are not limited to the temperature measurement of a pan heated by a gas stove or the like, but can be applied to other technical fields that require non-contact measurement.

It is a schematic explanatory drawing which shows embodiment of the temperature measurement module concerning this invention. It is a block diagram of the temperature measurement module shown in FIG. It is explanatory drawing which shows a process sequence. It is a graph which shows the radiation characteristic of hot air. 5A and 5B are graphs showing emissivity spectra of stainless steel and aluminum. 6A and 6B are graphs showing emissivity spectra of alumite and enamel. 7A and 7B are graphs showing emissivity spectra of the baking coating 1 and the baking coating 2. 8A and 8B are graphs respectively showing the temperature correlation between the first and second temperature detecting means. 9A and 9B are graphs showing the temperature correlation of the first and second temperature detecting means when the materials are different. 10A and 10B are an exploded perspective view and an exploded front view showing the measuring apparatus of the embodiment. 11A and 11B are a perspective view and a front view showing the measuring apparatus of the embodiment. It is a graph which shows the measurement result of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Temperature measurement module 20: Sensor part 21: Housing 22: 1st infrared sensor 23: 2nd infrared sensor 24: Reference temperature sensor 25: 1st filter 26: 2nd filter 30: Analog circuit part 40: Digital circuit part 41 : A / D converter 42: First temperature detection means 43: Second temperature detection means 44: Third temperature detection means 45: First addition means 46: Second addition means 47: Comparison means 50: Sample 51: Heater block 53: Plate-like heating element

Claims (8)

First infrared detecting means for measuring a specific wavelength range of infrared rays emitted from the measurement object;
Second infrared detection means for measuring a wavelength range longer than the wavelength range measured by the first infrared detection means;
First temperature detecting means for detecting the temperature of the object to be measured based on the ratio of the infrared intensity measured by the first infrared detecting means and the second infrared detecting means;
Second temperature detection means for detecting the temperature of the object to be measured based on the infrared intensity measured by the second infrared detection means;
Comparing means for comparing the temperature data output by the first temperature detecting means and the second temperature detecting means and outputting higher temperature data;
A temperature measurement module comprising: First infrared detecting means for measuring a specific wavelength range of infrared rays emitted from the measurement object;
Second infrared detection means for measuring a wavelength range longer than the wavelength range measured by the first infrared detection means;
Reference temperature detection means for measuring the ambient temperature of the first and second infrared detection means;
First temperature detecting means for detecting the temperature of the object to be measured based on the ratio of the infrared intensity measured by the first infrared detecting means and the second infrared detecting means;
Second temperature detection means for detecting the temperature of the object to be measured based on the infrared intensity measured by the second infrared detection means;
Third temperature detecting means for detecting the ambient temperature based on measurement data of the reference temperature detecting means;
First addition means for adding the temperature data of the first temperature detection means and the third temperature detection means;
Second addition means for adding the temperature data of the second temperature detection means and the third temperature detection means;
Comparing means for comparing the temperature data output by the first adding means and the second adding means, respectively, and outputting higher temperature data;
A temperature measurement module comprising:   The temperature measurement module according to claim 1 or 2, wherein the measurement wavelength range of the first infrared detection means is 3.0 µm to 4.2 µm.   4. The temperature measurement module according to claim 1, wherein a measurement wavelength region of the second infrared detection means is 8.0 μm to 13 μm. After measuring the specific wavelength range of the infrared ray radiated by the measurement object with the first infrared detection means, and measuring the wavelength range longer than the wavelength range measured with the first infrared detection means with the second infrared detection means ,
The temperature of the object to be measured is detected by the first temperature detecting means based on the ratio of the infrared intensity measured by the first infrared detecting means and the second infrared detecting means, and the infrared measured by the second infrared detecting means Based on the intensity, the temperature of the object to be measured is detected by the second temperature detecting means,
Next, the temperature data output by the first temperature detection means and the second temperature detection means are compared by a comparison means, and higher temperature data is output. A specific wavelength range of infrared rays emitted from the measurement object is measured by the first infrared detection means, and a wavelength range longer than the wavelength range measured by the first infrared detection means is measured by the second infrared detection means, After measuring the ambient temperature of the first and second infrared detecting means with reference temperature detecting means,
Infrared intensity measured by the second infrared detecting means by detecting the temperature of the object to be measured by the first temperature detecting means based on the ratio of the infrared intensity measured by the first infrared detecting means and the second infrared detecting means. And the second temperature detecting means detects the temperature of the object to be measured, and the ambient temperature is detected by the third temperature detecting means based on the measurement data of the reference temperature detecting means,
Next, the temperature data of the first temperature detection means and the third temperature detection means are summed by the first addition means, and the temperature data of the second temperature detection means and the third temperature detection means are summed by the second addition means,
Finally, the temperature measurement method characterized in that the temperature data output by the first addition means and the second addition means are compared, and the comparison means outputs higher temperature data.   The temperature measuring method according to claim 5 or 6, wherein the measurement wavelength range of the first infrared detecting means is 3.0 µm to 4.2 µm. The temperature measuring method according to any one of claims 5 to 7, wherein a measurement wavelength region of the second infrared detecting means is 8.0 µm to 13 µm.

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