Gas measurement device and gas measurement method

Abstract

A gas measurement device (5) comprises: an absorbance measurement device (10) that emits a detection light into a reaction vessel (2) for generating methane gas, and measures the absorbance of the detection light that has passed through the gas atmosphere inside the reaction vessel (2); an absorbance data analysis unit (21) that spectrally analyzes the absorbance data measured by the absorbance measurement device (10); a peak detection unit (22) that detects a plurality of peak values from the absorbance spectrum analyzed by the absorbance data analysis unit (21); and a pressure calculation unit (23) that calculates the pressure inside the reaction vessel (2) on the basis of the intensity ratio of two peak values among the plurality of peak values detected by the peak detection unit (22).

Description

Gas measurement device and gas measurement method

[0001] The present invention relates to a gas measurement device and a gas measurement method.

[0002] Patent Document 1 listed below discloses a gas concentration measuring device comprising: a laser that emits laser light of a wavelength and intensity according to the drive current and temperature; a wavelength stabilizing device that modulates the drive power supply of the laser at a predetermined temperature and at an arbitrary amplitude centered on a predetermined current value to stabilize the laser light at the center of an absorption line of a specific gas; a measurement gas cell that contains the specific gas to be measured and keeps the temperature of the specific gas constant; a photodetector that detects the intensity of transmitted light obtained by passing laser light of an arbitrary amplitude through the measurement gas cell; and measurement means that performs phase-sensitive detection of a specific component in the signal from the detector and measures the concentration of the specific gas in the measurement gas cell from changes in the detection signal corresponding to the modulation amplitude.

[0003] Japanese Patent Application Publication No. 5-256769

[0004] However, when focusing on one of the absorption spectral lines of methane gas, the absorption coefficient has a value that depends on the total pressure of the atmosphere, so when measuring the concentration in places where the air pressure changes drastically, such as coal mines or plants, there is a problem that accurate concentration measurement cannot be performed unless a separate pressure sensor is installed to monitor the pressure and correction is made based on that value.In the above-mentioned conventional technology, instead of installing a pressure sensor, the above problem is solved by installing a measurement gas cell that contains the specific gas to be measured and keeps the temperature of the specific gas constant, but there is a problem that installing the measurement gas cell is costly.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a gas measurement device and a gas measurement method that can measure a specific gas in a reaction vessel where the pressure changes without providing a pressure sensor.

[0006] A gas measurement device according to one aspect of the present invention includes an absorbance measurement device that irradiates a detection light into a reaction vessel generating gas and measures the absorbance of the detection light that has passed through a gas atmosphere in the reaction vessel; an absorbance data analysis unit that performs spectral analysis of the absorbance data measured by the absorbance measurement device; a peak detection unit that detects a plurality of peak values ​​from the absorbance spectrum analyzed by the absorbance data analysis unit; and a pressure calculation unit that calculates the pressure in the reaction vessel based on an intensity ratio of two peak values ​​among the plurality of peak values ​​detected by the peak detection unit.

[0007] Furthermore, the gas measurement device according to one aspect of the present invention may include a gas concentration calculation unit that calculates the concentration of the gas based on the peak value of the absorbance at a specific wavelength analyzed by the absorbance data analysis unit and the pressure inside the reaction vessel calculated by the pressure calculation unit, and a gas concentration output unit that outputs the concentration of the gas calculated by the gas concentration calculation unit.

[0008] Furthermore, the gas measurement device according to an aspect of the present invention may further include a gas concentration output unit that outputs the concentration of the gas calculated by the gas concentration calculation unit.

[0009] Furthermore, the gas measurement device according to one aspect of the present invention may include a data comparison unit that compares the peak value of absorbance with table data that corresponds to the concentration of the gas at a predetermined reference pressure that has been stored in advance.

[0010] In addition, in a gas measurement device according to one aspect of the present invention, the gas concentration calculation unit may include a peak value normalization unit that converts and normalizes the peak value of the absorbance at a specific wavelength analyzed by the absorbance data analysis unit to a peak value at a predetermined reference pressure from the pressure inside the reaction vessel calculated by the pressure calculation unit, and the data comparison unit may compare the normalized peak value of the absorbance with table data that is stored in advance and in which the peak value of the absorbance at the reference pressure corresponds to the concentration of the gas.

[0011] In the gas measurement device according to an aspect of the present invention, the peak detection unit may detect two adjacent peak values ​​from the absorbance spectrum analyzed by the absorbance data analysis unit.

[0012] In addition, in a gas measurement device according to one aspect of the present invention, when multiple pairs of peak values ​​of the two adjacent points are detected within a predetermined wavelength range, the peak detection unit may select the pair having the largest difference between the peak values ​​of the two adjacent points.

[0013] A gas measurement method according to one aspect of the present invention includes an absorbance measurement step of irradiating a detection light into a reaction vessel generating gas and measuring the absorbance of the detection light that has passed through a gas atmosphere in the reaction vessel; an absorbance data analysis step of performing spectral analysis on the absorbance data measured in the absorbance measurement step; a peak detection step of detecting a plurality of peak values ​​from the absorbance spectrum analyzed in the absorbance data analysis step; and a pressure calculation step of calculating the pressure in the reaction vessel based on an intensity ratio of two peak values ​​among the plurality of peak values ​​detected in the peak detection step.

[0014] According to the above aspect of the present invention, it is possible to measure a specific gas in a reaction vessel where the pressure changes without providing a pressure sensor.

[0015] 1 is a configuration diagram of a methane generation device according to one embodiment; FIG. 2 is a graph showing an example of an absorption spectrum of methane gas according to one embodiment; FIG. 3 is a graph showing the relationship between the intensity ratio (I1 / I2) of two peak values ​​and pressure according to one embodiment; and FIG. 4 is a graph showing the relationship between methane concentration and absorbance at each pressure according to one embodiment.

[0016] Hereinafter, a gas measurement device and a gas measurement method according to an embodiment of the present invention will be described in detail with reference to the drawings. First, an overview of the embodiment of the present invention will be described, and then the embodiment of the present invention will be described in detail.

[0017] [Summary] In the gas concentration measurement device of Patent Document 1, laser light emitted from a semiconductor laser is split by an optical splitter and transmitted to a reference gas cell and a measurement gas cell. The light that passes through the reference gas cell is received by a detector, and the received signal reaches a bipolar constant-current power supply via a lock-in amplifier and an integrator. This bipolar constant-current power supply then passes a positive or negative current to a Peltier element to control the temperature of the semiconductor laser and stabilize the emission of the laser light. The light that passes through the measurement gas cell is received by a photodetector, and the received signal is sent to a lock-in amplifier. Next, a divider and a signal processor process the signal to determine the pressure and gas concentration.

[0018] As described above, conventional gas concentration measurement devices require the installation of a measurement gas cell. Furthermore, in order to control the output of the semiconductor laser, this gas concentration measurement device requires the installation of a reference gas and a gas cell for sealing the reference gas separately.

[0019] In an embodiment of the present invention, a gas measurement device and a gas measurement method irradiate a detection light into a reaction vessel generating gas and measure the absorbance of the detection light that passes through the gas atmosphere in the reaction vessel. Next, the measured absorbance data is subjected to spectral analysis, and two peak values ​​are detected from the analyzed absorbance spectrum. The pressure in the reaction vessel is then calculated based on the intensity ratio of the two detected peak values. This allows the pressure to be estimated from the absorbance peak value, eliminating the need to install a pressure sensor. Furthermore, it also eliminates the need to remove the pressure sensor during heat treatment, such as sterilization, inside the reaction vessel. Furthermore, because gas extraction, as in a gas chromatograph, is not required, impurities can be prevented from being mixed into the reaction vessel. Furthermore, it is possible to accurately estimate the concentration of a specific gas in a reaction vessel where the pressure changes.

[0020] 1 is a configuration diagram of a methane generator 1 according to one embodiment. As shown in FIG. 1, the methane generator 1 includes a reaction vessel 2, a gas supply device 3, a generated gas extraction device 4, and a gas measurement device 5.

[0021] The reaction vessel 2 cultures methanogens in a culture solution 6 . Methane-producing bacteria include Methanobacterium alcaliphilum, Methanobacterium bryantii, Methanobacterium congolense, Methanobacterium defluvii, Methanobacterium espanolae, Methanobacterium formicicum, Methanobacterium ivanovii, Methanobacterium palustre, Methanobacterium thermaggregans, Methanobacterium uriginosum, Methanobacterium uliginosum), Methanobrevibacter acididurans, Methanobrevibacter arboriphilicus, Methanobrevibacter gottschalkii, Methanobrevibacter olleyae, Methanobrevibacter ruminantium, Methanobrevibacter smithii, Methanobrevibacter woesei, Methanobrevibacter wolinii, Methanothermobacter marburgensis marburgensis, Methanothermobacter thermoautotrophicusMethanothermobacter thermoautotrophicus, Methanothermobacter thermoflexus, Methanothermobacter thermophilics, Methanothermobacter wolfeii, Methanothermus sociabilis, Methanocorpusculum bavaricum, Methanocorpusculum parvum, Methanoculleus chikuoensis, Methanoculleus submarinus, Methanogenium frigidum, Methanogenium liminatans Examples of the fungal pathogen include Methanogenium marinum, Methanomicrobium mobile, Methanocaldococcus jannaschii, Methanococcus aeolicus, Methanococcus maripaludis, Methanococcus vannielii, Methanococcus voltaei, Methanothermococcus thermolithotrophicus, and the like.

[0022] The reactor 2 of this embodiment cultivates strains of methanogens such as Methanobacteriales, Methanomicrobiales, Methanocellales, and Methanomassillicoccales. These hydrogen-utilizing methanogens can also be found in anaerobic groundwater, and carbon dioxide (CO ) is introduced into anaerobic groundwater containing methanogens. ２ ) and hydrogen gas (H ２ Methane can be obtained by adding a mixed gas of the above two gases. That is, the reaction vessel 2 stores a culture solution 6 (e.g., anaerobic groundwater) containing a medium for cultivating methanogens. The reaction vessel 2 is in an anaerobic state, with the amount of oxygen present reduced as much as possible.

[0023] The gas supply device 3 opens the valve 3a and supplies carbon dioxide and hydrogen gas required by the methanogens to the reaction vessel 2. ２ / CO ２ A mixed gas (for example, 80 vol. %:20 vol. % in volume ratio) is introduced into the gas phase portion of the reaction vessel 2 and pressurized to a predetermined pressure, and the cultivation of methanogens is initiated.

[0024] The product gas extraction device 4 opens the valve 4a based on the measurement results of the gas measurement device 5, and extracts the methane produced by the methanogens (for example, hydrogen-utilizing methanogens). The product gas extraction device 4 extracts the product gas from the gas phase in the reaction vessel 2 and stores it in an external tank (not shown). After the methane extraction is complete, the valve 4a is closed and the H ２ / CO ２ The mixed gas is supplied to the reaction vessel 2, where the methanogens are cultured and methane is produced.

[0025] Before starting the cultivation of methanogens (H ２ / CO ２ Before supplying the mixed gas to the reaction vessel 2, an inert gas may be supplied from the gas supply device 3 or the like into the reaction vessel 2. By supplying the inert gas (gas purging), the inside of the reaction vessel 2 can be made anaerobic. Examples of the inert gas include nitrogen gas, argon gas, and helium gas.

[0026] The reaction vessel 2 contains a culture medium 6 and H ２ / CO ２ An agitation mechanism 8 is provided to agitate and mix the area of ​​the gas-liquid interface 7 with the mixed gas (reactant gas). The agitation mechanism 8 is equipped with a stirring blade and ruffles the gas-liquid interface 7 of the culture solution 6, thereby promoting dissolution of the reactant gas into the culture solution 6. Note that, as long as the area of ​​the gas-liquid interface 7 can be increased, a mechanism that vibrates the reaction vessel 2 itself may be used, for example.

[0027] The gas measurement device 5 measures and outputs the concentration of methane gas generated in the reaction vessel 2. The measurement results of the gas measurement device 5 are managed by peripheral devices (not shown) of the reaction vessel 2, enabling long-term operation (long-term production of methane) of the methane generation device 1. The gas measurement device 5 includes an absorbance measurement device 10, an information processing unit 11, and a concentration output unit 12.

[0028] The absorbance measuring device 10 irradiates the reaction vessel 2 producing methane gas with detection light and measures the absorbance of the detection light that has passed through the gas phase containing the gas in the reaction vessel 2, i.e., the gas atmosphere in the reaction vessel 2 (absorbance measurement process). The measurement target in this embodiment is methane gas, and it is preferable to use at least one of infrared and near-infrared light as the detection light. However, the measurement target is not limited to methane gas. When a specific gas other than methane gas is to be tested, it is preferable to use detection light of a wavelength suitable for that specific gas.

[0029] The absorbance measuring device 10 can be, for example, a probe type that is inserted into the reaction vessel 2. The probe type absorbance measuring device 10 has a light-emitting section and a light-receiving section for detection light at the base end of the probe, and a reflecting section at the tip of the probe that reflects the detection light toward the base end. An air hole is provided between the base end and the tip of the probe, and the gas in the reaction vessel 2 that passes through this air hole can be irradiated with detection light to measure its absorbance.

[0030] The information processing unit 11 includes a device control unit 20, an absorbance data analysis unit 21, a peak detection unit 22, a pressure calculation unit 23, and a gas concentration calculation unit 24 (a peak value normalization unit 24a and a data collating unit 24b). These are functionally separate, but in terms of physical (hardware) components, they may be configured by the same device (for example, a processing unit such as a PC) or by multiple devices.

[0031] The absorbance data analysis unit 21, peak detection unit 22, pressure calculation unit 23, and gas concentration calculation unit 24 process the measurement data of the absorbance measurement device 10. The device control unit 20 controls the operation of the absorbance measurement device 10 and also controls the operation of the valve 3a of the gas supply device 3, the valve 4a of the product gas extraction device 4, and other peripheral devices (not shown) of the reaction vessel 2, based on the processing results of the measurement data of the absorbance measurement device 10. During the reaction, it is preferable to close the valves 3a and 4a to keep the inside of the reaction vessel 2 sealed.

[0032] The absorbance data analysis unit 21 performs spectral analysis on the absorbance data measured by the absorbance measurement device 10 (absorbance data analysis step). Fig. 2 is a graph showing an example of the absorption spectrum of methane gas according to one embodiment. As shown in Fig. 2, the absorption spectrum of methane gas shows multiple characteristic peak values ​​I1, I2, and I3 in the infrared to near-infrared wavelength range.

[0033] The peak detection unit 22 detects two peak values ​​from the absorbance spectrum analyzed by the absorbance data analysis unit 21 (peak detection step). Specifically, the peak detection unit 22 detects two adjacent peak values, including the highest peak value I1, from the absorbance spectrum analyzed by the absorbance data analysis unit 21. Detecting two adjacent peak values ​​narrows the detection range of the absorbance spectrum and reduces the load on the calculation process. The peak value can be detected from the point where the slope of the absorbance is zero or changes from + to -.

[0034] As shown in Figure 2, when multiple pairs of adjacent peak values ​​(e.g., pairs I1 and I2, pairs I1 and I3) are detected within a predetermined wavelength range, the peak detection unit 22 selects the pair (I1 and I2) with the largest difference between the adjacent peak values. This results in a more pronounced change in the peak value intensity ratio (I1 / I2), which will be described later, and improves the accuracy of subsequent pressure estimation. Note that if a specific wavelength at which a characteristic peak value appears is known in advance, the pair of two peak values ​​at that specific wavelength may be selected.

[0035] The pressure calculation unit 23 calculates the pressure inside the reaction vessel 2 based on the intensity ratio (I1 / I2) of the two peak values ​​detected by the peak detection unit 22 (pressure calculation step). FIG. 3 is a graph showing the relationship between the intensity ratio (I1 / I2) of the two peak values ​​and the pressure according to one embodiment. As shown in FIG. 3, there is a correlation between the intensity ratio (I1 / I2) of the two peak values ​​and the pressure. The pressure calculation unit 23 calculates the pressure at the time of spectrum acquisition based on the relationship between the intensity ratio (I1 / I2) of the two peak values ​​and the pressure shown in FIG. 3.

[0036] The gas concentration calculation unit 24 calculates the concentration of the gas based on the peak value of absorbance at the specific wavelength analyzed by the absorbance data analysis unit 21 (I2 in this embodiment) and the pressure inside the reaction vessel 2 calculated by the pressure calculation unit 23 (gas concentration calculation step). Note that the peak value of absorbance at the specific wavelength may be I1, but there is another peak value I3 nearby, which may affect the peak value. For this reason, the gas concentration calculation unit 24 refers to I2.

[0037] The gas concentration calculation unit 24 includes a peak value normalization unit 24a that converts and normalizes the peak value (I2 in this embodiment) of absorbance at a specific wavelength analyzed by the absorbance data analysis unit 21 from the pressure inside the reaction vessel 2 calculated by the pressure calculation unit 23 to a peak value at a predetermined reference pressure, and a data comparison unit 24b that compares the normalized peak value of absorbance with pre-stored table data in which the peak value of absorbance at the reference pressure corresponds to the concentration of the gas.

[0038] FIG. 4 is a graph showing the relationship between methane concentration and absorbance at various pressures according to an embodiment. As shown in FIG. 4, the relationship between methane concentration and absorbance exhibits linearity with a slope that varies depending on the pressure. In other words, when the methane concentration is constant, the ratio between absorbance and pressure at each pressure is constant. Therefore, the peak value normalization unit 24a can normalize the absorbance to the reference pressure (1 atm in this example) and convert the absorbance (I2 in this example) to a peak value at 1 atm. The data collating unit 24b then stores table data that stores the relationship between the methane concentration at 1 atm and the calibration curve of absorbance. The methane concentration is calculated from the absorbance converted to 1 atm obtained by the peak value normalization unit 24a.

[0039] The concentration output unit 12 outputs the concentration of methane gas calculated by the gas concentration calculation unit 24 (gas concentration output step). The concentration output unit 12 is, for example, a display device. Note that the concentration output unit 12 may output not only the concentration of methane gas but also the pressure inside the reaction vessel 2 obtained during the calculation.

[0040] As described above, the gas measurement device 5 according to this embodiment can estimate the pressure inside the reaction vessel 2 by comparing the intensity ratio of two adjacent absorbance peak values ​​in the absorbance spectrum. This makes it possible to estimate the pressure inside the reaction vessel 2 without using a pressure sensor. Furthermore, there is no need to separately install a reference gas and a gas cell for sealing the reference gas, and the pressure inside the reaction vessel 2 can be estimated using only the acquired spectrum data. Furthermore, since the absorbance, which is pressure-dependent, can be corrected using the estimated pressure, gas concentrations can be compared under the same pressure conditions.

[0041] As described above, the gas measurement device 5 according to this embodiment includes an absorbance measurement device 10 that irradiates the inside of the reaction vessel 2 producing methane gas with detection light and measures the absorbance of the detection light that has passed through the gas atmosphere inside the reaction vessel 2, an absorbance data analysis unit 21 that performs spectral analysis of the absorbance data measured by the absorbance measurement device 10, a peak detection unit 22 that detects two peak values ​​I1 and I2 from the absorbance spectrum analyzed by the absorbance data analysis unit 21, and a pressure calculation unit 23 that calculates the pressure inside the reaction vessel 2 based on the intensity ratio (I1 / I2) of the two peak values ​​detected by the peak detection unit 22.

[0042] According to this configuration, a specific gas can be measured without installing a pressure sensor in a reaction vessel 2 where the pressure changes. In other words, since the pressure can be estimated from the peak value of absorbance, the installation of a pressure sensor is not necessary. Also, there is no need to remove the pressure sensor when performing heat treatment for sterilization inside the reaction vessel 2. Furthermore, since there is no need to extract a gas sample like in a gas chromatograph, it is possible to prevent impurities from being mixed into the reaction vessel. Furthermore, it is possible to accurately estimate the concentration of a specific gas in a reaction vessel where the pressure changes.

[0043] Furthermore, the gas measurement method according to this embodiment includes an absorbance measurement step of irradiating detection light into the reaction vessel 2 that generates gas and measuring the absorbance of the detection light that has passed through the gas atmosphere in the reaction vessel 2; an absorbance data analysis step of performing spectral analysis of the absorbance data measured in the absorbance measurement step; a peak detection step of detecting two peak values ​​I1 and I2 from the absorbance spectrum analyzed in the absorbance data analysis step; and a pressure calculation step of calculating the pressure inside the reaction vessel 2 based on the intensity ratio (I1 / I2) of the two peak values ​​detected in the peak detection step.

[0044] According to this configuration, it is also possible to measure a specific gas in the reaction vessel 2 where the pressure changes without providing a pressure sensor.

[0045] While the preferred embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the above-described embodiments. The shapes and combinations of the components shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0046] For example, the measurement target is not limited to methane gas. Similar to the above-described methane gas, hydrocarbons, nitrogen compounds, and sulfur compounds that exhibit near-infrared and infrared absorption can also be used as measurement targets. Note that if the relationship between the peak intensity ratio (I1 / I2) and pressure and the relationship between the gas concentration and absorbance at each pressure are known, pressure correction can be performed without using a pressure sensor, and the gas concentration can be quantitatively evaluated. Therefore, the measurement target is not limited to gases that exhibit near-infrared and infrared absorption.

[0047] Furthermore, for example, the peak detection unit 22 is not limited to a configuration that detects only two peak values. For example, the peak detection unit 22 may initially detect three or more peak values, select the two most suitable peak values ​​from among them, and use those peak values. Furthermore, the peak detection unit 22 may use one or more peak values ​​that were not selected to correct the pressure or gas concentration.

[0048] Note that part or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes.

[0049] (Supplementary Note 1) A gas measurement device comprising: an absorbance measurement device that irradiates a detection light into a reaction vessel that generates a gas, and measures the absorbance of the detection light that has passed through a gas atmosphere in the reaction vessel; an absorbance data analysis unit that performs spectral analysis of the absorbance data measured by the absorbance measurement device; a peak detection unit that detects a plurality of peak values ​​from the absorbance spectrum analyzed by the absorbance data analysis unit; and a gas concentration output unit that outputs the concentration of the gas in the reaction vessel based on an intensity ratio of two peak values ​​out of the plurality of peak values ​​detected by the peak detection unit.

[0050] 1... Methane generation apparatus, 2... Reaction vessel, 3... Gas supply apparatus, 3a... Valve, 4... Produced gas extraction apparatus, 4a... Valve, 5... Gas measurement apparatus, 6... Culture solution, 7... Gas-liquid interface, 8... Stirring mechanism, 10... Absorbance measurement apparatus, 11... Information processing section, 12... Concentration output section, 20... Apparatus control section, 21... Absorbance data analysis section, 22... Peak detection section, 23... Pressure calculation section, 24... Gas concentration calculation section, 24a... Peak value normalization section, 24b... Data collating section, CO ２ ...carbon dioxide, H ２ ...hydrogen gas, I1...peak value, I2...peak value, I3...peak value

Claims

1. A gas measurement device comprising: an absorbance measurement device that irradiates a detection light into a reaction vessel that generates gas, and measures the absorbance of the detection light that has passed through the gas atmosphere in the reaction vessel; an absorbance data analysis unit that performs spectral analysis of the absorbance data measured by the absorbance measurement device; a peak detection unit that detects multiple peak values ​​from the absorbance spectrum analyzed by the absorbance data analysis unit; and a pressure calculation unit that calculates the pressure in the reaction vessel based on the intensity ratio of two peak values ​​out of the multiple peak values ​​detected by the peak detection unit.

2. The gas measuring device according to claim 1, further comprising a gas concentration calculation unit that calculates the concentration of the gas based on the peak value of the absorbance at a specific wavelength analyzed by the absorbance data analysis unit and the pressure inside the reaction vessel calculated by the pressure calculation unit.

3. The gas measurement device according to claim 2, further comprising a gas concentration output section that outputs the gas concentration calculated by the gas concentration calculation section.

4. A gas measuring device as described in claim 2, wherein the gas concentration calculation unit is provided with a data comparison unit that compares the peak value of absorbance with table data in which the peak value of absorbance at a predetermined reference pressure stored in advance corresponds to the concentration of the gas.

5. The gas measurement device of claim 4, wherein the gas concentration calculation unit includes a peak value normalization unit which converts and normalizes the peak value of absorbance at a specific wavelength analyzed by the absorbance data analysis unit from the pressure inside the reaction vessel calculated by the pressure calculation unit to a peak value at a predetermined reference pressure, and the data comparison unit compares the normalized peak value of absorbance with table data which is stored in advance and in which the peak value of absorbance at the reference pressure corresponds to the concentration of the gas.

6. A gas measurement device according to any one of claims 1 to 5, wherein the peak detection section detects two adjacent peak values ​​from the absorbance spectrum analyzed by the absorbance data analysis section.

7. The gas measurement device according to claim 6, wherein when the peak detection section detects a plurality of pairs of peak values ​​of the two adjacent points within a predetermined wavelength range, the peak detection section selects the pair having the largest difference between the peak values ​​of the two adjacent points.

8. A gas measurement method comprising: an absorbance measurement step of irradiating a detection light into a reaction vessel generating gas, and measuring the absorbance of the detection light that has passed through the gas atmosphere in the reaction vessel; an absorbance data analysis step of performing spectral analysis of the absorbance data measured in the absorbance measurement step; a peak detection step of detecting a plurality of peak values ​​from the absorbance spectrum analyzed in the absorbance data analysis step; and a pressure calculation step of calculating the pressure in the reaction vessel based on an intensity ratio of two peak values ​​out of the plurality of peak values ​​detected in the peak detection step.

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