JP6168172B2 - Infrared gas analyzer - Google Patents

Description

  The present invention relates to an infrared gas analyzer that performs analysis based on the amount of infrared light transmitted through the sample cell by supplying the sample gas into the sample cell and irradiating the sample cell with infrared light. It is.

Infrared gas analyzers may be used when measuring concentrations of SO ₂ components, NO _x components, CO components, CO ₂ components, etc. as measurement target components contained in sample gas such as exhaust gas. The infrared gas analyzer is equipped with, for example, a sample cell, and the sample gas is supplied into the sample cell and irradiated with infrared light, thereby analyzing based on the amount of infrared light transmitted through the sample cell. (For example, refer to Patent Document 1 below).

  The sample gas may contain a component (interference component) having an infrared absorption wavelength region that overlaps at least part of the wavelength with respect to the infrared absorption wavelength region of the measurement target component. When such an interference component is contained in the sample gas, there is a problem that the accuracy of analysis is reduced due to the interference of the wavelengths of the measurement target component and the interference component.

  Therefore, in the infrared gas analyzer, a filter unit for removing the wavelength of the interference component is provided between the sample cell and the detector for receiving the infrared light transmitted through the sample cell. There is something that is. As the filter unit, for example, a gas filter in which a gas containing an interference component is enclosed is used, and infrared light transmitted through the sample cell is received by the detector via the gas filter.

JP 2005-69870 A

  In the infrared gas analyzer equipped with the filter unit as described above, when there are a plurality of interference components with respect to the measurement target component, a gas in which the plurality of interference components are mixed is sealed in the filter unit (gas filter). It will be.

  However, when a plurality of interference components are mixed as described above, the interference characteristics are difficult to be constant, and the filter unit may not function sufficiently. In particular, when the infrared absorption wavelength regions of a plurality of interference components overlap at least at some wavelengths, there is a problem that the above problems are likely to occur and the accuracy of analysis is likely to be reduced.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an infrared gas analyzer capable of performing analysis with high accuracy.

The infrared gas analyzer according to the present invention performs analysis based on the amount of infrared light transmitted through the sample cell by supplying the sample gas into the sample cell and irradiating the sample cell with infrared light. an infrared gas analyzer, the above-described infrared light enters through the sample cell, a filter unit for removing the wavelength of the interference component with respect to the measurement target component in the sample gas, infrared transmitted through the filter portion A detector for detecting light, and the filter unit is provided with a plurality of sealed chambers in which different gases respectively corresponding to a plurality of interference components are individually sealed, and an infrared beam transmitted through the sample cell. By sequentially transmitting light through the plurality of enclosure chambers, only the wavelength of the interference component corresponding to the gas enclosed in each enclosure chamber is removed and detected by the detector. What has become And features.

  According to such a configuration, gases corresponding to a plurality of interference components are individually enclosed in the plurality of enclosure chambers, and the infrared light transmitted through the sample cell passes through the plurality of enclosure chambers. Therefore, the interference characteristics tend to be constant as compared with the case where a plurality of interference components are mixed. Thereby, since the function as a filter part is fully demonstrated and the wavelength of an interference component can be favorably removed from the infrared light which permeate | transmitted the sample cell, it can analyze accurately.

  The plurality of enclosure chambers may be arranged in a line along an incident direction of infrared light transmitted through the sample cell.

  According to such a configuration, the infrared light transmitted through the sample cell sequentially passes through the plurality of enclosure chambers arranged in a line along the incident direction of the infrared light. Thereby, since the wavelength of the interference component corresponding to the gas sealed in each sealing chamber is sequentially removed from the infrared light transmitted through the sample cell, the wavelength of each interference component can be reliably removed. . Therefore, analysis can be performed with higher accuracy.

  The volume of the sealed chamber corresponding to the interference component having a larger amount contained in the sample gas may be set larger.

  According to such a configuration, a larger amount of interference components can be sealed in a sealing chamber corresponding to an interference component having a larger amount contained in the sample gas. Thereby, since the wavelength of the interference component can be better removed from the infrared light transmitted through the sample cell, the analysis can be performed with higher accuracy.

  The infrared absorption wavelength ranges of interference components corresponding to the plurality of enclosure chambers may overlap at least at some wavelengths.

  According to such a configuration, even a combination of interference components whose analysis accuracy is likely to be reduced can be analyzed with high accuracy. That is, when the infrared absorption wavelength regions of a plurality of interference components overlap at least at some wavelengths, the interference characteristics are difficult to be made constant by using a filter unit in which the plurality of interference components are mixed and sealed. , Analysis accuracy is likely to decrease. Even in such a case, if a filter unit in which gases corresponding to a plurality of interference components are individually enclosed in a plurality of enclosure chambers is used, the wavelength of the interference component is excellent from the infrared light transmitted through the sample cell. Therefore, the analysis can be performed with high accuracy.

The measurement target component in the sample gas may include at least one of an SO ₂ component, a NO _x component, a CO component, and a CO ₂ component.

According to such a configuration, when at least one of the SO ₂ component, the NO _x component, the CO component, and the CO ₂ component is contained in the sample gas as the measurement target component, the analysis can be performed with high accuracy. Since each of the above components exists in a region where the infrared absorption wavelength range is close to each other, when at least one of these components is a measurement target component and at least one of the remaining components is an interference component, measurement is performed. Wavelength interference between the target component and the interference component tends to occur, and the accuracy of analysis tends to decrease. Even in such a case, according to the present invention, since the wavelength of the interference component can be satisfactorily removed from the infrared light transmitted through the sample cell, the analysis can be performed with high accuracy.

  The sample gas may be exhaust gas.

  According to such a configuration, when analyzing the measurement target component contained in the exhaust gas, the wavelength of the interference component with respect to the measurement target component can be satisfactorily removed by the filter unit, so that the analysis can be performed with high accuracy. it can. Therefore, an infrared gas analyzer suitable for exhaust gas analysis can be provided.

In particular, since the exhaust gas contains a large amount of CO ₂ component, when the sample gas is exhaust gas, the configuration is such that at least the CO ₂ component is sealed in one sealing chamber of the filter unit. Analysis can be performed with high accuracy.

  According to the present invention, since the gas corresponding to each of the plurality of interference components is individually sealed in the plurality of enclosure chambers, the interference characteristics tend to be constant, and the wavelength of the interference component from the infrared light transmitted through the sample cell. Can be removed satisfactorily, so that the analysis can be performed with high accuracy.

It is the schematic which shows the structural example of the infrared gas analyzer which concerns on one Embodiment of this invention. It is sectional drawing which shows the structural example of a filter part. It is sectional drawing which shows another structural example of a filter part. It is a figure which shows the result of an effect confirmation test.

FIG. 1 is a schematic diagram showing a configuration example of an infrared gas analyzer according to an embodiment of the present invention. This infrared gas analyzer detects the infrared light transmitted through the sample cell 1 by the detector 3 by supplying the sample gas into the sample cell 1 and irradiating the sample cell 1 with infrared light from the light source 2. The analysis is based on the light quantity (infrared light intensity). As the sample gas, for example, exhaust gas containing SO ₂ component, NO _x component, CO component or CO ₂ component as a measurement target component can be exemplified, and sample gas collected from an exhaust gas flow path such as a flue is used. Can do.

  In the infrared gas analyzer according to this embodiment, by alternately supplying the reference gas and the sample gas into the sample cell 1, the amount of infrared light transmitted through the reference gas and the infrared light transmitted through the sample gas are reduced. Analysis can be performed based on the amount of light. For example, air is used as the reference gas. The reference gas and the sample gas are alternately supplied into the sample cell 1 through the common supply path 4, and are alternately filled in the sample cell 1 and exhausted.

  The sample gas flow path 5 for supplying the sample gas is connected to the supply path 4 via the electromagnetic valve SV3. The electromagnetic valve SV3 is composed of, for example, a three-way valve, and in addition to the supply path 4 and the sample gas flow path 5, an exhaust path 7 for exhausting gas is connected. Therefore, by controlling the electromagnetic valve SV3, switching between the state in which the sample gas is supplied from the sample gas flow path 5 to the supply path 4 and the state in which the sample gas is exhausted from the sample gas flow path 5 to the exhaust path 7 is possible. It can be done.

  The reference gas flow path 6 for supplying the reference gas is connected to the supply path 4 via the electromagnetic valve SV4. The electromagnetic valve SV4 is composed of, for example, a three-way valve, and the exhaust passage 7 is connected in addition to the supply passage 4 and the reference gas passage 6. Therefore, by switching the solenoid valve SV4, switching between the state in which the reference gas is supplied from the reference gas flow path 6 to the supply path 4 and the state in which the reference gas is exhausted from the reference gas flow path 6 to the exhaust path 7 can be performed. It can be done.

  At the time of sample measurement, with the sample gas introduced into the sample gas flow channel 5 and the reference gas introduced into the reference gas flow channel 6, the electromagnetic valve SV3 and the electromagnetic valve SV4 are in a constant cycle (for example, a cycle of 10 seconds). By switching, the reference gas and the sample gas are alternately supplied to the supply path 4. As a result, the operation of alternately replacing the gas in the sample cell 1 with the reference gas or the sample gas is repeated.

Further, in the infrared gas analyzer according to the present embodiment, the zero point and the span point can be calibrated by introducing the calibration gas such as the zero gas and the span gas into the supply path 4. As the zero gas, for example, a gas (N ₂ gas or the like) that does not include the measurement target component can be used. On the other hand, as the span gas, a gas containing a measurement target component at a known concentration can be used.

  The sample gas flow path 5 is provided with, for example, an electromagnetic valve SV1 composed of a three-way valve, and the sample gas or the calibration gas (zero gas or span gas) is introduced into the sample gas flow path 5 by controlling the electromagnetic valve SV1. The sample cell 1 can be supplied via the supply path 4. On the other hand, the reference gas flow path 6 is provided with, for example, an electromagnetic valve SV2 composed of a three-way valve, and the sample gas or the calibration gas (zero gas) is introduced into the reference gas flow path 6 by controlling the electromagnetic valve SV2. The sample cell 1 can be supplied via the supply path 4.

  At the time of calibration, the solenoid valve SV1 introduces the calibration gas (zero gas or span gas) into the sample gas flow path 5 and the solenoid valve SV2 introduces the calibration gas (zero gas) into the reference gas flow path 6 so that the solenoid valve SV3 and solenoid valve SV4 are switched at a constant cycle (for example, a cycle of 10 seconds).

  For example, when the zero point is calibrated, the gas in the sample cell 1 is replaced with the zero gas by introducing the zero gas into the sample gas channel 5 and the reference gas channel 6. On the other hand, when the span point is calibrated, the span gas is introduced into the sample gas flow path 5 and the zero gas is introduced into the reference gas flow path 6 so that the gas in the sample cell 1 is alternately replaced with the span gas or the zero gas. Repeated.

  The supply path 4 is provided with a humidity control unit 8 for adjusting the water vapor concentration in the gas. The humidity control unit 8 is composed of, for example, a humidity controller including a semipermeable membrane water vapor exchange material, and takes water vapor in the gas into the material or releases water vapor into the gas according to the water vapor concentration in the gas. It has a humidity control function. However, the humidity control unit 8 is not limited to the configuration provided with the semipermeable membrane water vapor exchange material, and may be configured by a humidity controller that realizes the humidity control function by another configuration.

  A branch portion 41 is provided upstream of the humidity control section 8 in the supply path 4, and the bypass flow path 9 branches from the supply path 4 at the branch section 41. The branch portion 41 is provided with an electromagnetic valve SV5 made of, for example, a three-way valve. The electromagnetic valve SV5 constitutes a switching unit, and by controlling the electromagnetic valve SV5, the gas flow path can be switched to the humidity control section 8 side or the bypass flow path 9 side. However, the switching unit is not limited to the one configured by the electromagnetic valve SV5, and the gas channel may be switched to the humidity control unit 8 side or the bypass channel 9 side by another configuration.

  The bypass channel 9 joins the supply channel 4 at a junction 42 provided on the downstream side of the humidity control unit 8 in the supply channel 4. Therefore, by controlling the solenoid valve SV5 and switching the gas flow path to the bypass flow path 9 side, the humidity control section 8 can be bypassed and gas can be supplied to the sample cell 1.

  At the time of sample measurement, the sample gas supplied from the sample gas channel 5 to the supply channel 4 and the reference gas supplied from the reference gas channel 6 to the supply channel 4 are respectively led to the humidity control unit 8 side. After the water vapor concentration is adjusted in the humidity control unit 8, the water is supplied into the sample cell 1. On the other hand, at the time of calibration, the calibration gas (zero gas or span gas) supplied from the sample gas channel 5 to the supply channel 4 and the calibration gas (zero gas) supplied from the reference gas channel 6 to the supply channel 4 are bypassed. It is guided to the flow path 9 side and supplied into the sample cell 1 without passing through the humidity control section 8.

  A sector 10 is provided between the sample cell 1 and the light source 2 for intermittently blocking infrared light from the light source 2. The rotation position of the sector 10 is controlled by a drive unit (not shown) such as a motor. The detector 3 is filled with a gas containing a measurement target component, and can detect an infrared light intensity of an absorption wavelength unique to the measurement target component by an internal pressure change.

  A detection signal in the detector 3 is input to the signal processing unit 11. The signal processing unit 11 performs measurement based on the detection signal from the detector 3 when the sample gas is supplied to the sample cell 1 and the detection signal from the detector 3 when the reference gas is supplied to the sample cell 1. Processing for measuring the concentration of the target component is performed. This measurement result can be displayed on the display unit 12 including, for example, a liquid crystal display.

  In the present embodiment, a filter unit 100 configured by, for example, a gas filter is provided between the sample cell 1 and the detector 3. The filter unit 100 is configured such that gas is sealed therein, so that infrared light transmitted through the sample cell 1 is incident on the filter unit 100, passes through the filter unit 100, and is detected by the detector 3. It has become.

  The infrared light that has passed through the sample cell 1 passes through the filter unit 100 and is detected by the detector 3, whereby the wavelength of the interference component with respect to the measurement target component in the sample gas can be removed. That is, since the wavelength of the interference component can be absorbed by the filter unit 100, the wavelength of the measurement target component can be detected by the detector 3 in a state where the influence of the interference component is reduced.

  FIG. 2A is a cross-sectional view illustrating a configuration example of the filter unit 100. The filter unit 100 is configured by enclosing gas in a cylindrical main body 110. In this example, gases corresponding to two interference components are individually sealed in two sealing chambers 111 and 112 provided in the main body 110.

When the CO component is a measurement target component, for example, _{two of a} CO ₂ component and an N ₂ O component can be used as interference components. In this case, a gas containing a CO ₂ component can be enclosed in one enclosure chamber 111, and a gas containing an N ₂ O component can be enclosed in the other enclosure chamber 112. In the main body 110, the enclosure chambers 111 and 112 are partitioned by a plurality of transparent plates 113, for example. Each transparent plate 113 can be formed of a material having a wide transmission wavelength region such as calcium fluoride.

  The transparent plates 113 are provided in parallel to each other so as to extend in a direction perpendicular to the incident direction D of infrared light transmitted through the sample cell 1. In this example, the distances between the adjacent transparent plates 113 are not constant, but are set to different distances so that the respective enclosure chambers 111 and 112 have different volumes.

  In the present embodiment, since the infrared light transmitted through the sample cell 1 is transmitted through each of the enclosure chambers 111 and 112, the interference characteristics are lower than when a plurality of interference components are mixed. It tends to be constant. Thereby, the function as the filter unit 100 is sufficiently exhibited, and the wavelength of the interference component can be satisfactorily removed from the infrared light transmitted through the sample cell 1, so that the analysis can be performed with high accuracy.

  In particular, in this embodiment, the infrared light transmitted through the sample cell 1 sequentially passes through the enclosure chambers 111 and 112 arranged in a line along the incident direction D of the infrared light. As a result, the wavelength of the interference component corresponding to the gas sealed in each of the sealing chambers 111 and 112 is sequentially removed from the infrared light transmitted through the sample cell 1, so that the wavelength of each interference component is reliably removed. can do. Therefore, analysis can be performed with higher accuracy.

In this example, CO ₂ component and _{N 2} O component is an interference component contained in the sample gas is often towards CO ₂ component, towards the _{N 2} O component is small. Correspondingly, the volume of the sealed chamber 111 in which the gas containing the CO ₂ component is sealed is set larger than that of the sealed chamber 112 in which the gas containing the N ₂ O component is sealed. Yes. That is, the volume of the sealed chamber corresponding to the interference component having a larger amount contained in the sample gas is set larger.

  Therefore, a larger amount of interference components can be sealed in the enclosure chamber corresponding to the interference components having a larger amount contained in the sample gas. Thereby, since the wavelength of the interference component can be removed more favorably from the infrared light transmitted through the sample cell 1, analysis can be performed with higher accuracy. The volume ratio of each enclosure chamber 111 may substantially coincide with the ratio of the content of interference components corresponding to each enclosure chamber 111 in the sample gas.

The infrared absorption wavelength regions of the CO ₂ component and N ₂ O component, which are interference components in this example, overlap at least at some wavelengths. As described above, the infrared absorption wavelength regions of the interference components corresponding to the plurality of enclosure chambers 111 and 112 may overlap at least at some wavelengths. In this case, even if it is a combination of interference components in which the accuracy of analysis is likely to decrease, analysis can be performed with high accuracy.

  That is, when the infrared absorption wavelength regions of a plurality of interference components overlap at least at some wavelengths, the interference characteristics are difficult to be made constant by using a filter unit in which the plurality of interference components are mixed and sealed. , Analysis accuracy is likely to decrease. Even in such a case, if the filter unit 100 in which gases corresponding to a plurality of interference components are individually enclosed in the plurality of enclosure chambers 111 and 112 is used, interference from infrared light transmitted through the sample cell 1 occurs. Since the wavelength of the component can be removed satisfactorily, analysis can be performed with high accuracy.

  The interference component corresponding to each of the plurality of enclosures 111 and 112 is not limited to a configuration in which the infrared absorption wavelength region overlaps at least a part of the wavelengths, for example, a component that reacts with each other or a component that easily reacts with each other. Further, a combination of interference components in which the accuracy of analysis is likely to be lowered in other modes may be used.

  FIG. 2B is a cross-sectional view illustrating another configuration example of the filter unit 100. The filter unit 100 is configured by enclosing a gas in a cylindrical main body 120. In this example, gases corresponding to three interference components are individually enclosed in three enclosure chambers 121, 122, and 123 provided in the main body 120.

  In the main body 120, the enclosure chambers 121, 122, and 123 are partitioned by a plurality of transparent plates 124, for example. Each transparent plate 124 can be formed of a material having a wide transmission wavelength range such as calcium fluoride.

  The transparent plates 124 are provided in parallel to each other so as to extend in a direction orthogonal to the incident direction D of infrared light transmitted through the sample cell 1. Thereby, the infrared light transmitted through the sample cell 1 is sequentially transmitted through the enclosing chambers 121, 122, 123 arranged in a line along the incident direction D of the infrared light. In this example, the distances between the adjacent transparent plates 124 are not constant, but are set to different distances, so that the enclosing chambers 121, 122, and 123 have different volumes.

  In this case, similarly to the example of FIG. 2A, the volume may be set to be larger in the sealed chamber corresponding to the interference component having a larger amount contained in the sample gas. Moreover, the infrared absorption wavelength range of the interference component corresponding to each of the plurality of enclosure chambers 121, 122, 123 may overlap at least at some wavelengths.

  Even in the filter unit 100 having the configuration as shown in FIG. 2B, the same effect as in the case of FIG. 2A can be obtained. That is, the enclosure chambers for individually enclosing the gas corresponding to each of the plurality of interference components are not limited to the two enclosure chambers 111 and 112 as shown in FIG. 2A, but three enclosure chambers 121 and 122 as shown in FIG. 2B. 123, or four or more depending on the number of interference components.

  Note that the plurality of enclosure chambers are not limited to configurations having different volumes as in the examples of FIGS. 2A and 2B, and may be configured to have the same volume, for example. In addition, the transparent plates 113 and 124 that partition each enclosure chamber are not limited to a configuration that extends in a direction orthogonal to the incident direction D of the infrared light transmitted through the sample cell 1, and for example, at least one transparent plate 113, 124 may be inclined with respect to the orthogonal direction.

  In the above embodiment, the case where the sample gas is exhaust gas has been described. In this case, when the measurement target component contained in the exhaust gas is analyzed, the wavelength of the interference component with respect to the measurement target component can be favorably removed by the filter unit 100, so that the analysis can be performed with high accuracy. Therefore, an infrared gas analyzer suitable for exhaust gas analysis can be provided.

In particular, since the exhaust gas contains a large amount of CO ₂ component, when the sample gas is exhaust gas, at least the CO ₂ component is sealed in one sealing chamber of the filter unit 100, Analysis can be performed with higher accuracy.

Further, according to the infrared gas analyzer as described above, when at least one of the SO ₂ component, the NO _x component, the CO component, and the CO ₂ component is contained in the sample gas as the measurement target component, the analysis can be performed with high accuracy. It can be carried out. Since each of the above components exists in a region where the infrared absorption wavelength range is close to each other, when at least one of these components is a measurement target component and at least one of the remaining components is an interference component, measurement is performed. Wavelength interference between the target component and the interference component tends to occur, and the accuracy of analysis tends to decrease. Even in such a case, according to the infrared gas analyzer as described above, since the wavelength of the interference component can be satisfactorily removed from the infrared light transmitted through the sample cell 1, the analysis is performed with high accuracy. be able to.

However, the infrared gas analyzer according to the present invention can perform analysis using not only exhaust gas but also other various gases as sample gases. In this case, the infrared gas analyzer according to the present invention can be applied to the analysis of a sample gas containing a component other than the SO ₂ component, NO _x component, CO component, or CO ₂ component as a measurement target component.

  In addition, the infrared gas analyzer according to the present invention is not limited to the configuration including the humidity control unit 8 and the bypass channel 9, and may be a configuration not including these. Further, the configuration is not limited to the configuration in which the reference gas and the sample gas are alternately supplied into the sample cell 1, for example, the sample cell and the reference cell are provided individually, and the sample gas in the sample cell and the reference gas in the reference cell are provided. The gas may be irradiated with infrared light.

FIG. 3 is a diagram showing the results of the effect confirmation test. Hereinafter, with reference to FIG. 3, the result of the effect confirmation test when the sample gas including the CO component as the measurement target component is analyzed using the filter unit 100 as illustrated in FIG. 2A will be described. In FIG. 3, as a result of measurement using an infrared gas analyzer (CO meter), the measured concentration error (interference value) with respect to the actual concentration of CO component contained in the sample gas is expressed as interference component. It is shown in association with the concentration of the CO ₂ component.

First, when a filter unit in which a CO ₂ component and an N ₂ O component are mixed and sealed as an interference component with respect to a CO component that is a measurement target component, a measurement result as indicated by L1 in FIG. An error of -3 ppm occurred.

Next, as shown in FIG. 2A, when the filter unit 100 in which the CO ₂ component and the N ₂ O component are individually enclosed in different enclosures 111 and 112 is used, the measurement result as indicated by L2 in FIG. Thus, the error was within the range A of ± 1 ppm regardless of the concentration of the CO ₂ component.

  From the results of the effect confirmation test as described above, it is understood that the analysis can be performed with high accuracy by performing the analysis using the filter unit 100 as shown in FIG. 2A. According to this result, even when analysis is performed using the filter unit 100 as shown in FIG.

DESCRIPTION OF SYMBOLS 1 Sample cell 2 Light source 3 Detector 4 Supply path 5 Sample gas flow path 6 Reference gas flow path 7 Exhaust path 8 Humidity control part 9 Bypass flow path 10 Sector 11 Signal processing part 12 Display part 41 Branch part 42 Merge part 100 Filter part 110 Main body 111, 112 Enclosure chamber 113 Transparent plate 120 Main body 121, 122, 123 Enclosure chamber 124 Transparent plate SV1-SV5 Solenoid valve

Claims (9)

An infrared gas analyzer for performing analysis based on the amount of infrared light transmitted through the sample cell by supplying sample gas into the sample cell and irradiating the sample cell with infrared light,
Infrared light transmitted through the sample cell is incident, and a filter unit for removing the wavelength of the interference component with respect to the measurement target component in the sample gas ;
A detector for detecting infrared light transmitted through the filter unit ;
The filter unit is provided with a plurality of enclosure chambers in which different gases respectively corresponding to a plurality of interference components are individually enclosed, and infrared light transmitted through the sample cell sequentially passes through the plurality of enclosure chambers. infrared gas by passing through, characterized in that only the wavelength of the interference component corresponding to the gas sealed in the sealed chamber is adapted to be detected by the detector is removed by the sealed chamber Analysis equipment.   The infrared gas analyzer according to claim 1, wherein the plurality of enclosure chambers are arranged in a line along an incident direction of infrared light transmitted through the sample cell.   3. The infrared gas analyzer according to claim 1, wherein a volume of the sealed chamber corresponding to an interference component having a larger amount contained in the sample gas is set larger.   The infrared gas analyzer according to any one of claims 1 to 3, wherein the infrared absorption wavelength regions of the interference components respectively corresponding to the plurality of enclosure chambers overlap at least at a part of the wavelengths. 5. The infrared gas analyzer according to claim 1, wherein the measurement target component in the sample gas includes at least one of an SO ₂ component, an NO _x component, a CO component, and a CO ₂ component. .   6. The infrared gas analyzer according to claim 1, wherein the sample gas is exhaust gas. 7. The infrared ray according to claim 1, wherein a volume ratio of the plurality of enclosure chambers is substantially equal to a content ratio of interference components corresponding to each enclosure chamber in the sample gas. Gas analyzer. The infrared gas analyzer according to claim 1, wherein the filter unit includes a main body in which the plurality of enclosure chambers are provided. The infrared gas analyzer according to claim 8, wherein the plurality of enclosure chambers are partitioned by a plurality of transparent plates provided in the main body.

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