Analytical apparatus and analytical method

Abstract

The present invention appropriately performs explosion-proof measures for an analysis device while suppressing the consumption amount of a purge gas. This analysis device (100) comprises a filling part (3), an irradiation part (5), a propagation part (7), a housing (1), a purge gas introduction part (40), and an explosion-proof gas introduction part (20). The filling part (3) is filled with a sample gas (SG) containing a gas to be measured. The irradiation part (5) emits measurement light (L) used to analyze the gas to be measured. The propagation part (7) is provided between the filling part (3) and the irradiation part (5), and forms a propagation space (TS) for causing the measurement light (L) emitted from the irradiation part (5) to propagate toward the filling part (3). The housing (1) stores the filling part (3), the irradiation part (5), and the propagation part (7). The purge gas introduction part (40) introduces a purge gas (PG) into the propagation space (TS). The explosion-proof gas introduction part (20) introduces an explosion-proof gas (EP) into the internal space of the housing (1).

Description

[Technical Field]

[0001] The present invention relates to an analytical device for analyzing a target gas contained in a sample gas, and to a method for analyzing the target gas using this analytical device. [Background technology]

[0002] Conventionally, analytical devices are known that irradiate a sample gas with measurement light and analyze the target gas based on the intensity of the measurement light absorbed by the target gas contained in the sample gas. In this analytical device, the sample gas is filled into a predetermined cell, and the analysis is performed based on the intensity of the measurement light that passes through the cell. To prevent the measurement light from being absorbed by gases present in the surrounding environment before it reaches the predetermined cell, it is preferable to fill the optical path from the light source that outputs the measurement light to the cell with a gas that does not contain components that absorb the measurement light. This gas is called a purge gas. In a measuring device that uses carbon dioxide contained in the atmosphere as the target gas, there is a method of generating a gas that does not contain the target gas by passing the sample gas (atmosphere) through a carbon dioxide adsorbent such as zeolite and a substance that adsorbs polar substances such as silica gel (see, for example, Patent Document 1).

[0003] Furthermore, a device is known in which the above-mentioned analytical instruments are housed in a single enclosure. In this device, explosion-proof measures may be implemented. Specifically, explosion-proof measures are taken by filling the internal space of the enclosure housing the analytical instruments with explosion-proof gas. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2016-14658 [Overview of the project] [Problems that the invention aims to solve]

[0005] The gas used as a purge gas is generally an inert gas. Therefore, the purge gas can also be used as an explosion-proof gas to fill the internal space of the enclosure. However, purge gas is more expensive than explosion-proof gas. Also, filling the internal space of the enclosure with explosion-proof gas requires a large amount of gas. Therefore, filling the internal space of the enclosure, including the optical path of the measurement light, with purge gas requires a large amount of purge gas, which increases the operating cost of the analytical instrument.

[0006] On the other hand, if the internal space of the housing, including the optical path of the measurement light, is filled with explosion-proof gas, the measurement light may be absorbed by components in the explosion-proof gas before it reaches the cell containing the gas to be measured.

[0007] The objective of the present invention is to provide an apparatus in which an analytical instrument for analyzing a target gas is housed in a casing, while reducing the consumption of purge gas and filling the optical path of the measurement light with purge gas, and while appropriately implementing explosion-proof measures for the apparatus. [Means for solving the problem]

[0008] Several embodiments for solving the problem are described below. These embodiments can be combined as needed. The analytical apparatus according to the present invention is an analytical apparatus for analyzing a target gas. The analytical apparatus comprises a filling section, an irradiation section, a propagation section, a housing, a purge gas introduction section, and an explosion-proof gas introduction section. ,of The system is equipped with the following components: The filling section is filled with a sample gas containing the gas to be measured. The irradiation section irradiates the gas to be measured with measurement light used for analysis. The propagation section is located between the filling section and the irradiation section and forms a propagation space that propagates the measurement light irradiated from the irradiation section to the filling section. The housing houses the filling section, the irradiation section, and the propagation section. The purge gas introduction section introduces purge gas into the propagation space. The explosion-proof gas introduction section introduces explosion-proof gas into the internal space of the housing.

[0009] In the analytical apparatus described above, purge gas is introduced only into the propagation space, which is the optical path of the measurement light. Since the propagation space is a small volume space, the consumption of purge gas can be kept to a minimum. In addition, a different explosion-proof gas is introduced into the large internal space of the enclosure. Explosion-proof gas is inexpensive and suitable for explosion-proof measures, so explosion-proof measures for the internal space of the enclosure can be implemented inexpensively and appropriately. Furthermore, by introducing explosion-proof gas into the internal space of the enclosure, the various components housed inside the enclosure can be cooled.

[0010] The analytical apparatus may further include a partition plate. The partition plate separates the internal space of the housing into a first internal space containing the irradiation and propagation sections, and a second internal space containing the filling section. By providing a partition plate that separates the internal space of the housing into a first internal space containing the irradiation and propagation sections and a second internal space containing the filling section, the irradiation and propagation sections can be spatially separated from the filling section, which becomes hot.

[0011] The housing and propagation section may be configured as an internal pressure explosion-proof container. This allows for safe explosion protection of the internal space of the housing and propagation section.

[0012] The analyzer may further include a pressure switch. The pressure switch detects whether the pressure in the filling section exceeds a predetermined pressure that is less than the pressure in the internal space of the housing. This allows for the detection of whether the pressure in the filling section has become higher than the internal space of the housing, and whether the gas filling the filling section may leak into the internal space of the housing.

[0013] The analytical device may further include a first differential pressure gauge. The first differential pressure gauge measures the difference between the pressure near the outlet of the purge gas in the propagation space and the pressure in the internal space of the enclosure. This allows for reliable detection of whether the pressure in the propagation space is higher than the pressure in the internal space of the enclosure, that is, whether or not there is a possibility of explosion-proof gas entering the propagation space.

[0014] The analytical device may further include a second differential pressure gauge. The second differential pressure gauge measures the difference between the pressure near the explosion-proof gas outlet in the internal space of the enclosure and the pressure outside the enclosure. This allows for reliable detection of whether the pressure inside the enclosure is higher than the pressure outside the enclosure, that is, whether external gas has entered the internal space of the enclosure and the explosion-proof measures are inadequate.

[0015] The propagation unit may be located in the propagation space and may have a mirror that guides the measurement light into the filling unit. In this case, the analytical device may further include a jig. The jig allows a tool for adjusting the mirror to reach the mirror's position in the propagation space. This ensures that the tool for adjusting the mirror can be reached in the correct position even when the mirror is not visible.

[0016] The analytical apparatus may further include a fixing plate. The fixing plate secures the filling section, the irradiation section, and the propagation section. This prevents changes in the relative positions and orientations of the filling section, irradiation section, and propagation section due to flexing of the housing or other factors.

[0017] The analytical apparatus may further include a separation unit. The separation unit separates the purge gas from the gas. This allows for the easy and inexpensive generation of the purge gas.

[0018] The separation unit may be located outside the housing. This prevents components other than the purge gas contained in the gas from being discharged into the internal space of the housing.

[0019] The separation unit may be located inside the enclosure. In this case, the remaining gas, other than the purge gas, from the components separated by the separation unit may be used as the explosion-proof gas. This eliminates the need to provide separate gas lines for supplying the purge gas and for supplying the explosion-proof gas.

[0020] The analysis device may further include a first differential pressure gauge, a second differential pressure gauge, and a pressure switch. The first differential pressure gauge measures the difference between the pressure near the outlet of the purge gas in the propagation space and the pressure in the internal space of the housing. The second differential pressure gauge measures the difference between the pressure near the exhaust outlet of the explosion-proof gas in the internal space of the housing and the pressure outside the housing. The pressure switch detects whether the pressure in the filling part has reached a predetermined pressure or higher, which is lower than the pressure in the internal space of the housing. In this case, the first differential pressure gauge, the second differential pressure gauge, and the pressure switch measure the magnitude relationship between the pressure in the internal space of the housing and the pressure outside the housing, the magnitude relationship between the pressure in the propagation space and the pressure in the internal space of the housing, the magnitude relationship between the pressure in the propagation space and the pressure inside the filling part, and the magnitude relationship between the pressure in the internal space of the housing and the pressure inside the filling part. Thereby, the magnitude relationship of the pressures at a large number of locations can be efficiently measured by a small number of devices.

[0021] The measurement target gases are carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), sulfur dioxide (SO2), ammonia (NH3), nitrogen oxides (NOx), hydrogen chloride (HCl), water (H2O), ethane (C2H6), acetylene (C2H2), propane (C3H8), ethylene (C2H4), hexane (n-C6H 14 )), propylene (C3H6), hydrogen sulfide (H2S), isobutene (i-C4H8), methanol (CH3OH), phosgene (COCl2), butane (n-C4H 10 )), chloroethylene (C2H3Cl), methyl nitrite (CH3ONO), cyclohexane (C6H 12 )), butadiene (C4H6), isobutane (i-C4H 10 )), isopentane (i-C5H 12 )), toluene (C6H5CH3), hydrogen (H2), hydrogen fluoride (HF), trifluoropropene (C3H3F3). Thereby, in the analysis device, while suppressing the consumption amount of the purge gas, appropriate explosion-proof measures can be taken to safely analyze the above measurement target gases.

[0022] An analysis method according to another aspect of the present invention is an analysis method for a measurement target gas by an analysis device. The analysis device includes a filling unit filled with a sample gas containing the measurement target gas, an irradiation unit that irradiates measurement light used for analyzing the measurement target gas, a propagation unit provided between the filling unit and the irradiation unit that forms a propagation space for propagating the measurement light irradiated from the irradiation unit to the filling unit, a filling unit, an irradiation unit, and a housing that houses the filling unit, the irradiation unit, and the propagation unit. The analysis method includes the following steps. ◎ A step of introducing a purge gas into the propagation space. ◎ A step of introducing an explosion-proof gas into the internal space of the housing. ◎ A step of irradiating measurement light from the irradiation unit and propagating the measurement light through the propagation space to the filling unit filled with the sample gas. ◎ A step of analyzing the measurement target gas contained in the sample gas based on the measurement result of the measurement light that has passed through the sample gas filled in the filling unit.

[0023] In the above analysis method, the purge gas is introduced only into the propagation space that is the optical path of the measurement light. Since the propagation space is a space with a small volume, the consumption of the purge gas can be suppressed. In addition, an explosion-proof gas different from the purge gas is introduced into the internal space of the housing with a large volume. Since the explosion-proof gas is inexpensive and suitable for explosion-proof measures, the explosion-proof measures for the internal space of the housing can be implemented inexpensively and appropriately. Further, by introducing the explosion-proof gas into the internal space of the housing, each member housed in the internal space of the housing can be cooled. Furthermore, the measurement light passes through the propagation space filled with the purge gas and is guided to the filling unit filled with the sample gas. Thereby, it is possible to suppress the absorption of the measurement light in the propagation space while the measurement light reaches the filling unit. As a result, the measurement target gas can be accurately analyzed using the measurement light.

Advantages of the Invention

[0024] In an analysis device for a measurement target gas having a housing, it is possible to appropriately perform explosion-proof measures for the analysis device while suppressing the consumption of the purge gas and filling the optical path of the measurement light with the purge gas.

Brief Description of the Drawings

[0025] [Figure 1] Diagram showing the configuration of the analysis device. [Figure 2] Diagram showing the configuration of the jig. [Figure 3] Diagram schematically showing the state where the jig is attached to the propagation unit. [Figure 4] Diagram showing the gas flow configuration of the analysis device. [Figure 5] Diagram showing another example of the gas flow configuration of the analysis device.

Embodiments for Carrying Out the Invention

[0026] 1. First Embodiment (1) Configuration of the analysis device Hereinafter, the analysis device 100 will be described. First, using FIG. 1, the configuration of the analysis device 100 other than the configuration for introducing the purge gas PG and the explosion-proof gas EP will be described. FIG. 1 is a diagram showing the configuration of the analysis device other than the gas introduction portion. The analysis device 100 is, for example, a device that analyzes a measurement target gas contained in a sample gas SG such as exhaust gas generated from a flue.

[0027] Measurement target gases that can be measured by the analysis device 100 include, for example, carbon dioxide (CO2), carbon monoxide (CO), sulfur oxides (SOx) (e.g., sulfur dioxide (SO2)), ammonia (NH3), nitrogen oxides (NOx) (e.g., nitric oxide (NO), nitrogen dioxide (NO2), nitrous oxide (N2O), etc.), hydrogen chloride (HCl), water (H2O), various hydrocarbons (e.g., methane (CH4), ethane (C2H6), acetylene (C2H2), propane (C3H8), ethylene (C2H4), hexane (n-C6H 14 ), propylene (C3H6), isobutene (i-C4H 10 ), propane (C3H8), cyclohexane (C6H 12 ), butadiene (C4H6), isobutane (i-C4H 10 ), isopentane (i-C5H 12Examples include toluene (C6H5CH3), hydrogen sulfide (H2S), methanol (CH3OH), phosgene (COCl2), chloroethylene (C2H3Cl), methyl nitrite (CH3ONO), hydrogen (H2), hydrogen fluoride (HF), and trifluoropropene (C3H3F3). The target gas for measurement is not limited to one type; it may also be a mixed gas containing multiple of the above gases.

[0028] The analyzer 100 has a structure that isolates the components for analyzing the target gas from the external space, and fills the internal space containing the components of the analyzer 100 with a gas that does not contain highly flammable gases. Such a structure is called an "explosion-proof structure." In the following explanation, the gas that fills the internal space described above will be referred to as an "explosion-proof gas."

[0029] By making the analyzer 100 explosion-proof, the target gas can be safely analyzed even if the surrounding environment outside the analyzer 100 contains flammable gases. As shown in Figure 1, the analyzer 100 comprises a housing 1, a filling unit 3, an irradiation unit 5, a propagation unit 7, a partition plate 9, and a control unit 11.

[0030] The housing 1 constitutes the main body of the analyzer 100, and houses the filling unit 3, the irradiation unit 5, and the propagation unit 7 in its internal space. The housing 1 is configured as an internal pressure explosion-proof container. Specifically, the internal space of the housing 1 is filled with explosion-proof gas EP at a higher pressure than the external space of the housing 1. By configuring the housing 1 as an internal pressure explosion-proof container, the internal space of the housing 1 can be safely explosion-proofed. The housing 1 is provided with an outlet 13 near the location of the filling unit 3. The explosion-proof gas EP introduced into the internal space of the housing 1 is discharged from the outlet 13.

[0031] The filling unit 3 is a component having a sampling space SS. The sampling space SS of the filling unit 3 can be filled with a sample gas SG. To fill the sampling space SS with the sample gas SG, the filling unit 3 is provided with an inlet 31 for introducing the sample gas SG into the sampling space SS and an outlet 32 ​​for discharging the sample gas SG from the sampling space SS. During the analysis of the target gas contained in the sample gas SG, the sample gas SG continues to be filled into the sampling space SS from the inlet 31 and then discharged from the outlet 32.

[0032] The sampling space SS maintains a lower pressure than the internal space of the housing 1 and the propagation space TS of the propagation unit 7, including when filled with the sample gas SG. This prevents the sample gas SG filling the sampling space SS from leaking into the internal space of the housing 1 and the propagation space TS of the propagation unit 7, thereby enabling proper explosion-proof measures for the analytical device 100.

[0033] Furthermore, a first reflective member 33a and a second reflective member 33b are provided in the sampling space SS. The first reflective member 33a and the second reflective member 33b cause multiple reflections of the measurement light L incident on the sampling space SS, and then propagate it toward the propagation space TS (described later) of the propagation unit 7. This makes it possible to increase the optical path length of the measurement light L passing through the sample gas SG filled in the sampling space SS.

[0034] The first reflective member 33a is positioned close to the propagation unit 7 in the sampling space SS. The first reflective member 33a reflects the measurement light L and propagates the measurement light L toward the second reflective member 33b. It also propagates the multiple-reflected measurement light L toward the propagation unit 7. Therefore, the first reflective member 33a is, for example, a member (for example, a mirror) that can reflect the measurement light L and has a passage hole for the measurement light L at a predetermined position. In this first reflective member 33a, the measurement light L propagating from the propagation unit 7 passes through the passage hole and enters the sampling space SS. The measurement light L that enters the sampling space SS undergoes multiple reflections between the first reflective member 33a and the second reflective member 33b, and then returns to the propagation unit 7 through the passage hole in the first reflective member 33a.

[0035] The second reflective member 33b is provided at a position away from the propagation unit 7 in the sampling space SS. The second reflective member 33b reflects the measurement light L toward the first reflective member 33a. The second reflective member 33b is, for example, a member that reflects the measurement light L, such as a mirror.

[0036] The irradiation unit 5 generates measurement light L. The measurement light L generated from the irradiation unit 5 is guided to the filling unit 3 by the propagation unit 7. The irradiation unit 5 is composed of multiple light sources 51a to 51d. Each of the multiple light sources 51a to 51d outputs multiple elemental lights L1 to L4 with different wavelength ranges. The multiple light sources 51a to 51d are, for example, laser oscillators such as semiconductor laser devices.

[0037] The elemental beams L1 to L4 generated from multiple light sources 51a to 51d are multiplexed within the propagation space TS of the propagation unit 7 and propagate toward the filling unit 3 as measurement beam L. That is, the measurement beam L is composed of multiple elemental beams L1 to L4 with different wavelength ranges. Because the measurement beam L is composed of multiple elemental beams L1 to L4, for example, multiple types of target gases having absorption peaks in the wavelength ranges of each elemental beam L1 to L4 can be measured.

[0038] Furthermore, since the measurement light L is composed of multiple elemental light beams L1 to L4, it is possible to measure, for example, the effect of interfering gas components on a single target gas. Interfering gas components are components that have absorption peaks at the same or similar positions as some of the absorption peaks of the target gas, and as a result, affect the analysis results of the target gas. If the effect of interfering gas components can be measured, their influence can be removed from the measurement results of the measurement light L received by the detection unit 75 (described later), allowing for accurate analysis of the target gas. Note that "removal" includes not only completely eliminating the influence of interfering gas components, but also reducing the degree of influence compared to before removal.

[0039] The propagation section 7 is provided between the filling section 3 and the irradiation section 5. Specifically, as shown in Figure 1, the propagation section 7 has an L-shape, and multiple light sources 51a to 51d are fixed in a partially inserted state in the part corresponding to one side of the L-shape. On the other hand, the filling section 3 is fixed to the end of the other side of the L-shape of the propagation section 7 via an optical window W.

[0040] The propagation section 7 is configured as an internal pressure explosion-proof container and has a propagation space TS. The propagation space TS of the propagation section 7 is formed by hollowing out a metal block to create a space and then closing the space formed in the metal block with a lid member. The metal members (metal block, lid member) for constructing the propagation section 7 are, for example, aluminum members. When the propagation section 7 is constructed from aluminum members, the aluminum members are blackened by anodizing. In this way, a robust propagation section 7 can be easily formed. As described above, by configuring the propagation section 7 as an internal pressure explosion-proof container, the propagation space TS, which is the internal space of the propagation section 7, can be safely made explosion-proof.

[0041] Multiple mirrors are arranged in the propagation space TS of the propagation unit 7. The elemental light L1 to L4 output from the irradiation unit 5 has its propagation path altered by these mirrors and propagates to the filling unit 3. That is, the measurement light L propagates within the propagation space TS while being reflected by at least one mirror. Specifically, the propagation space TS contains a first mirror 71a, a second mirror 71b, a third mirror 71c, a fourth mirror 71d, and a fifth mirror 71e. In addition, the propagation space TS contains a first optical element 73a, a second optical element 73b, and a third optical element 73c.

[0042] The first mirror 71a reflects the elemental light L1 toward the first optical element 73a. The first optical element 73a reflects the elemental light L1 and transmits the elemental light L2. In other words, the first optical element 73a multiplexes the elemental light L1 and the elemental light L2. The elemental light L1 and the elemental light L2 multiplexed by the first optical element 73a travel along the same optical path toward the second mirror 71b.

[0043] The second mirror 71b reflects the elemental light L1 and elemental light L2, which are multiplexed by the first optical element 73a, toward the second optical element 73b. The second optical element 73b reflects the multiplexed elemental light L1 and elemental light L2, and transmits elemental light L3. In other words, the second optical element 73b multiplexes elemental light L1, elemental light L2, and elemental light L3. The elemental light L1 to L3, multiplexed by the second optical element 73b, travel along the same optical path toward the third mirror 71c.

[0044] The third mirror 71c reflects the elemental beams L1 to L3, which have been multiplexed by the second optical element 73b, toward the third optical element 73c. ​​The third optical element 73c reflects the multiplexed elemental beams L1 to L3 and transmits elemental beam L4. In other words, the third optical element 73c multiplexes elemental beams L1, L2, L3, and L4. The elemental beams L1 to L4, which have been multiplexed by the third optical element 73c, travel along the same optical path toward the fourth mirror 71d.

[0045] The fourth mirror 71d reflects the elemental beams L1 to L4, which are multiplexed by the third optical element 73c, toward the fifth mirror 71e. The elemental beams L1 to L4, which are multiplexed in this manner, become the measurement beam L.

[0046] The fifth mirror 71e changes the propagation path of the measurement light L, which is composed of multiplexed elemental light L1 to L4, in the direction of the arrangement of the filling section 3. The measurement light L, whose propagation path has been changed by the fifth mirror 71e, passes through the optical window W and propagates into the sampling space SS of the filling section 3. Since these mirrors are located within the propagation space TS, the inflow of unwanted gases from the outside is prevented, keeping the mirrors clean.

[0047] Furthermore, a detection unit 75 is positioned in the propagation space TS of the propagation unit 7. The detection unit 75 detects the measurement light L that has been incident on the sampling space SS and undergone multiple reflections. The detection unit 75 is, for example, a quantum photoelectric element. Other types of detection elements, such as semiconductor detection elements and thermal photodetectors like thermopiles, can also be used as the detection unit 75. As shown in Figure 1, a sixth mirror 71f is provided in the propagation space TS to change the propagation path of the measurement light L that has undergone multiple reflections in the sampling space SS and returned to the propagation unit 7, in the direction of the detection unit 75.

[0048] As described later, the propagation space TS is purged using purge gas PG. This allows the purge gas PG to circulate within the propagation space TS, keeping the first mirrors 71a to the sixth mirrors 71f and the detection unit 75, which are installed within the propagation space TS, clean.

[0049] The optical path of the measurement light L from the propagation section 7 to the filling section 3 is determined by the first mirror 71a to the sixth mirror 71f. The tilt angles of these mirrors are adjustable in order to properly propagate the measurement light L to the filling section 3. For example, the tilt angles of the first mirror 71a to the fourth mirror 71d can be adjusted by rotating the screw 711 (Figure 3) provided in the propagation space TS.

[0050] In order to enable manipulation of the screw 711, this embodiment uses a jig 80 that brings a tool T for manipulating the screw 711 to the screw 711 in the propagation space TS. As shown in Figure 2, the jig 80 has a main body 81, a through hole 83, and a handle 85. Figure 2 is a diagram showing the configuration of the jig.

[0051] The through-hole 83 is a hole provided that penetrates the main body 81. The through-hole 83 is positioned opposite the screw 711 provided on the mirror when the main body 81 is attached to the propagation unit 7. The jig 80 shown in Figure 2 has four through-holes 83. The handle 85 is gripped by the user when attaching the jig 80 to the propagation unit 7.

[0052] As shown in Figure 3, the jig 80 is attached to the propagation section 7 by fitting the main body 81 into a hole provided in the propagation section 7. When the jig 80 is attached to the propagation section 7, the through hole 83 faces the screws 711 provided in the first mirror 71a to the fourth mirror 71d. Therefore, by inserting the tool T into any of the through holes 83, the tip of the tool T can reach the screw 711. In this way, by using the jig 80 described above, even if the first mirror 71a to the fourth mirror 71d provided in the propagation space TS cannot be visually inspected, the tool T for adjusting these mirrors can be brought to the appropriate position. Figure 3 is a schematic diagram showing the jig attached to the propagation section.

[0053] Let's return to the explanation of the analytical apparatus 100 using Figure 1. The partition plate 9 separates the internal space of the housing 1 into a first internal space IS1 and a second internal space IS2. As shown in Figure 1, the first internal space IS1 contains the irradiation section 5 and the propagation section 7. On the other hand, the second internal space IS2 contains the filling section 3.

[0054] The filling section 3, where the sample gas SG is filled, becomes hot, while it is preferable to keep the irradiation section 5 and propagation section 7 from room temperature (the temperature when the irradiation section 5 and propagation section 7 are mounted in the housing 1) as stable as possible. This is because fluctuations in the temperature of the irradiation section 5 and propagation section 7 may cause the optical axis of the measurement light L, which has been appropriately adjusted in advance, to shift. Therefore, by providing a partition plate 9 in the internal space of the housing 1 that houses the filling section 3, irradiation section 5, and propagation section 7, the irradiation section 5 and propagation section 7 can be spatially separated from the high-temperature filling section 3, thereby suppressing temperature fluctuations in the irradiation section 5 and propagation section 7. As a result, it is possible to suppress the shifting of the optical axis of the measurement light L, which has been appropriately adjusted in advance.

[0055] As shown in Figure 1, the filling section 3, the irradiation section 5, and the propagation section 7 are not directly fixed to the housing 1, but are fixed on a single fixing plate 15, and are fixed to the housing 1 via the fixing plate 15.

[0056] The filling section 3, the irradiation section 5, and the propagation section 7 are appropriately positioned and oriented so that the measurement light L generated in the irradiation section 5 can reach the filling section 3 via the propagation section 7. If the filling section 3, the irradiation section 5, and the propagation section 7 were directly fixed to the housing 1, their relative positions and orientations might change due to the bending of the housing 1. Therefore, as in this embodiment, by fixing the filling section 3, the irradiation section 5, and the propagation section 7 on a common fixing plate 15, it is possible to suppress changes in the relative positions and orientations of the filling section 3, the irradiation section 5, and the propagation section 7 due to the bending of the housing 1. As a result, the measurement light L generated in the irradiation section 5 can reach the filling section 3 via the propagation section 7 (propagation space TS) without being affected by the bending of the housing 1.

[0057] The control unit 11 is a computer system composed of a CPU, a memory device (for example, RAM, ROM, etc.), and various interfaces. The control unit 11 may be a system equipped with each of the above devices individually, or it may be a System on Chip (SoC) that integrates each of the above devices onto a single chip. The control unit 11 controls the components of the analyzer 100. The control unit 11 also has a calculation unit 11a that performs calibration of the analyzer 100 and analysis of the target gas based on the intensity of the measurement light L detected by the detection unit 75.

[0058] Some or all of the control and information processing performed by the control unit 11 may be implemented by executing a program stored in the storage device of the computer system constituting the control unit 11. Alternatively, some of the control and information processing may be implemented in hardware.

[0059] The control unit 11 is connected to a display unit 111 that displays information about the analyzer 100, such as the analysis results of the target gas measured by the analyzer 100, and a display screen. The display unit 111 is, for example, a thin display such as a liquid crystal display or an organic EL display. The display unit 111 may also have an information input means such as a touch panel.

[0060] (2) Gas flow configuration of the analyzer Next, the gas flow configuration in the analyzer 100 will be explained using Figure 4. Figure 4 is a diagram showing the gas flow configuration of the analyzer. In order to make the analyzer 100 explosion-proof, the internal space of the housing 1, which houses the filling section 3, the irradiation section 5, and the propagation section 7, is filled with explosion-proof gas EP that does not contain flammable gas at a first pressure greater than the external pressure of the housing 1. In addition, the propagation space TS through which the measurement light L propagates is filled with purge gas PG that does not contain the target gas at a second pressure greater than the internal pressure of the housing 1, in order to suppress absorption of the measurement light L before it reaches the filling section 3.

[0061] Accordingly, the analyzer 100 includes an explosion-proof gas introduction unit 20 for introducing explosion-proof gas EP into the internal space of the housing 1, and a purge gas introduction unit 40 for introducing purge gas PG into the propagation space TS.

[0062] The explosion-proof gas introduction section 20 has a first gas line GL1 and a supply device 21. The inlet IN1 of the first gas line is connected to the external supply device 21. On the other hand, the outlet OUT1 of the first gas line GL1 is located at the top of the first internal space IS1 of the housing 1 and near the propagation section 7. The supply device 21 is a device that supplies explosion-proof gas EP to the first gas line GL1. The supply device 21 is, for example, a device that generates instrumentation air and is equipped with a compressor for compressing air and various filters for removing dust, oil, etc. contained in the air. In other words, in this embodiment, the explosion-proof gas EP is instrumentation air that does not contain flammable gases. When the analysis device 100 is in operation, the explosion-proof gas EP is constantly supplied from the supply device 21.

[0063] The explosion-proof gas introduction unit 20 having the above configuration constantly introduces explosion-proof gas EP from the upper part of the first internal space IS1 and near the propagation unit 7. Due to the presence of the partition plate 9, the explosion-proof gas EP introduced to the upper part of the first internal space IS1 and near the propagation unit 7 flows from the upper part to the lower part of the first internal space IS1 and enters the second internal space IS2 from the lower part of the first internal space IS1. The gas that enters the second internal space IS2 flows from the lower part to the upper part of the second internal space IS2 and is discharged from the outlet 13.

[0064] Since explosion-proof gas EP is continuously supplied when the analyzer 100 is in operation, explosion-proof gas EP is continuously supplied to the internal space of the housing 1 when the analyzer 100 is in operation and discharged from the outlet 13 in the flow described above. As a result, when the analyzer 100 is in operation, the internal space of the housing 1 is constantly filled with fresh explosion-proof gas EP at the first pressure.

[0065] Furthermore, by introducing the explosion-proof gas EP into the first internal space IS1 first, the unheated explosion-proof gas EP can reach the irradiation unit 5 and propagation unit 7 first. In addition, the presence of the partition plate 9 suppresses the heating of the explosion-proof gas EP by heat conduction from the high-temperature filling unit 3. As a result, the irradiation unit 5 and propagation unit 7 (especially the detection unit 75), which require cooling, can be cooled efficiently.

[0066] The purge gas introduction section 40 includes a second gas line GL2 and a separation section 41. The inlet IN2 of the second gas line GL2 is connected to the separation section 41. On the other hand, the outlet OUT2 of the second gas line GL2 is connected to the lower part of the propagation section 7. The inlet IN3 of the third gas line GL3 is connected to the upper part of the propagation section 7. The outlet OUT3 of the third gas line GL3 is located near the outlet OUT1 of the first gas line GL1.

[0067] The separation unit 41 separates the purge gas PG from the gas. In this embodiment, the separation unit 41 separates the purge gas PG from the instrumentation air supplied from the supply device 21.

[0068] The separation unit 41 is a component called an "N2 separator," which is made by filling a hollow member with, for example, a polyimide hollow fiber membrane or a gas separation membrane. The N2 separator introduces compressed air into the hollow fiber membrane or gas separation membrane and separates the air into a nitrogen-rich gas from which components other than nitrogen gas (including the gas to be measured) have been removed, and the remaining gas from which nitrogen has been removed. The separation unit 41, which is the N2 separator, discharges the nitrogen-rich gas as purge gas PG to the second gas line GL2. On the other hand, the separation unit 41 discharges the remaining gas to the outside.

[0069] The hollow fiber membranes described above are composed of, for example, polyimide, polyamide, polysulfone, cellulose acetate and its derivatives, polyphenylene oxide, polysiloxane, polymers that are microporous themselves, mixed matrix membranes, facilitated transport membranes, polyethylene oxide, polypropylene oxide, carbon membranes, zeolites, or mixtures thereof.

[0070] As shown in Figure 4, the separation unit 41 is located outside the housing 1. This allows the separation unit 41 to discharge the remaining gas to the outside of the housing 1. As a result, the remaining gas, which contains a large amount of oxygen, is prevented from being introduced into the internal space of the housing 1, thereby ensuring proper explosion protection of the internal space of the housing 1.

[0071] Alternatively, instead of generating purge gas PG using the separation unit 41 described above, a gas cylinder supplying purge gas PG may be connected to the inlet IN2 of the second gas line GL2. In other words, purge gas PG may be supplied directly from a gas cylinder. As the gas cylinder supplying purge gas PG, for example, a gas cylinder that supplies inert gas such as a nitrogen cylinder can be used.

[0072] Similar to the explosion-proof gas EP, the purge gas PG is continuously supplied to the second gas line GL2 when the analyzer 100 is in operation.

[0073] The purge gas introduction unit 40, having the above configuration, introduces purge gas PG from the bottom of the propagation space TS. The purge gas PG introduced from the bottom of the propagation space TS flows to the top of the propagation space TS and is discharged into the internal space of the housing 1 via the third gas line GL3. In addition, similar to the explosion-proof gas EP, the purge gas PG is supplied continuously when the analyzer 100 is in operation. Therefore, when the analyzer 100 is in operation, the purge gas PG is continuously supplied to the propagation space TS and discharged into the internal space of the housing 1 in the above flow. As a result, when the analyzer 100 is in operation, the propagation space TS is constantly filled with fresh purge gas PG at a second pressure greater than the pressure (first pressure) of the internal space of the housing 1.

[0074] As shown in Figure 4, the third gas line GL3 has a smaller diameter compared to the other gas lines. By reducing the diameter of the third gas line GL3, which is used to discharge the purge gas PG, the pressure of the purge gas PG in the propagation space TS can be easily increased.

[0075] The analytical device 100 includes a first differential pressure gauge 61 and a second differential pressure gauge 63. The first differential pressure gauge 61 and the second differential pressure gauge 63 have two ports and are devices that measure the pressure difference between the pressure at one port and the pressure at the other port.

[0076] One of the two ports of the first differential pressure gauge 61, port P1, is connected via the fourth gas line GL4 to the vicinity of the location where the third gas line GL3 is provided in the propagation space TS, and the other port P2 is connected to the internal space of the housing 1. In other words, the first differential pressure gauge 61 measures the difference between the pressure near the outlet of the purge gas PG in the propagation space TS and the pressure in the internal space of the housing 1.

[0077] The inventors of this case, through their investigation, found that the pressure near the outlet of the purge gas PG in the propagation space TS, which is filled with purge gas PG, is the lowest. Based on this finding, the pressure difference between the lowest pressure in the propagation space TS and the pressure in the internal space of the housing 1 is measured by the first differential pressure gauge 61. This allows the first differential pressure gauge 61 to reliably detect whether the pressure in the propagation space TS is higher than the pressure in the internal space of the housing 1, that is, whether or not there is a possibility of explosion-proof gas EP entering the propagation space TS. This is because if the lowest pressure in the propagation space TS is higher than the pressure in the internal space of the housing 1, it can be guaranteed that the pressure at other points in the propagation space TS is higher than the pressure in the internal space of the housing 1.

[0078] One of the two ports of the second differential pressure gauge 63, port P3, is connected via the fifth gas line GL5 to the vicinity of the outlet OUT1 of the first gas line GL1 in the internal space of the housing 1. The other port P4 is connected via the sixth gas line GL6 to the space outside the housing 1. In other words, the second differential pressure gauge 63 measures the difference between the pressure near the outlet of the explosion-proof gas EP in the internal space of the housing 1 and the pressure outside the housing 1.

[0079] The inventors of this case have found, through their investigation, that the pressure is lowest near the outlet (OUT1 of the first gas line GL1) for introducing the explosion-proof gas EP into the internal space of the housing 1, which is filled with explosion-proof gas EP. Based on this finding, the pressure difference between the lowest pressure inside the housing 1 and the pressure outside the housing 1 is measured using a second differential pressure gauge 63. This allows the second differential pressure gauge 63 to reliably detect whether the pressure inside the housing 1 is higher than the pressure outside the housing, that is, whether external gas has entered the internal space of the housing 1 and the explosion-proof measures are inadequate. This is because if the lowest pressure inside the housing 1 is higher than the pressure outside the housing 1, it can be guaranteed that the pressure at other points inside the housing 1 is higher than the pressure outside the housing 1.

[0080] Furthermore, if the second differential pressure gauge 63 indicates that the pressure inside the housing 1 is higher than the pressure outside the housing 1, and the first differential pressure gauge 61 indicates that the pressure inside the propagation space TS is higher than the pressure inside the housing 1, then it can be guaranteed that the pressure inside the propagation space TS is higher than the pressure outside the housing 1. In other words, it can be guaranteed that there is no possibility of gas from outside the housing 1 entering the propagation space TS.

[0081] The first differential pressure gauge 61 performs control regarding the supply of purge gas PG based on the detection result of whether the pressure in the propagation space TS is higher than the pressure in the internal space of the housing 1. The second differential pressure gauge 63 also performs control regarding the supply of explosion-proof gas EP based on the detection result of whether the pressure in the internal space of the housing 1 is higher than the pressure outside the housing.

[0082] The analyzer 100 is equipped with a pressure switch 65. The pressure switch 65 is connected to the outlet 32 ​​of the sample gas SG of the filling section 3. The pressure switch 65 detects whether the pressure in the sampling space SS of the filling section 3 has risen to or above a predetermined pressure that is lower than the pressure in the internal space of the housing 1. The pressure switch 65 may be an off-state when the pressure in the sampling space SS is lower than the predetermined pressure and an on-state when the pressure in the sampling space SS rises to or above the predetermined pressure, or it may be a pressure switch where the off and on states are reversed.

[0083] Furthermore, based on the state of the pressure switch 65, the pressure difference between the lowest pressure in the propagation space TS measured by the first differential pressure gauge 61 and the pressure in the internal space of the housing 1, it is possible to monitor whether the pressure in the propagation space TS of the propagation unit 7 is higher than the pressure in the sampling space SS. Specifically, for example, if the pressure switch 65 detects that the pressure in the sampling space SS is lower than the predetermined pressure mentioned above (for example, the pressure switch 65 is in the off state), and the first differential pressure gauge 61 detects that the lowest pressure in the propagation space TS is higher than the pressure in the internal space of the housing 1, it can be determined that the pressure in the propagation space TS is higher than the pressure in the sampling space SS.

[0084] As described above, the analyzer 100 measures four types of pressure relationships—the relationship between the pressure inside the housing 1 and the pressure outside the housing 1, the relationship between the pressure in the propagation space TS and the pressure inside the housing 1, the relationship between the pressure in the propagation space TS and the pressure in the sampling space SS, and the relationship between the pressure inside the housing 1 and the pressure in the sampling space SS—using three devices: a first differential pressure gauge 61, a second differential pressure gauge 63, and a pressure switch 65. In this way, the analyzer 100 efficiently measures the pressure relationships at numerous locations using a small number of devices.

[0085] The analyzer 100 is equipped with a pressure gauge 67. The pressure gauge 67 is connected to the outlet 32 ​​of the sample gas SG in the filling section 3 and measures the pressure in the sampling space SS. The pressure in the sampling space SS is used to correct the analysis results of the target gas contained in the sample gas SG filling the sampling space SS.

[0086] (3) Operation of the analyzer The operation of the analyzer 100 will be described below. To operate the analyzer 100, the introduction of purge gas PG into the propagation space TS of the propagation unit 7 is initiated. After the introduction of purge gas PG into the propagation space TS is initiated, the first differential pressure gauge 61 determines whether the pressure in the propagation space TS has reached the second pressure based on the pressure difference between the lowest pressure in the propagation space TS and the pressure in the internal space of the housing 1. The first differential pressure gauge 61 continues to supply purge gas PG until one hour has elapsed since the pressure in the propagation space TS reached the second pressure. The flow rate of purge gas PG introduced into the propagation space TS and the length of the first hour can be appropriately set to optimal values ​​based on the capacity of the propagation space TS, etc.

[0087] After the pressure in the propagation space TS reaches the second pressure, the supply of purge gas PG is continued for one hour. Then, while maintaining the supply of purge gas PG, the introduction of explosion-proof gas EP into the internal space of the housing 1 is started. After the introduction of explosion-proof gas EP into the internal space of the housing 1 is started, the second differential pressure gauge 63 determines whether the pressure in the internal space of the housing 1 has reached the first pressure based on the pressure difference between the lowest pressure in the internal space of the housing 1 and the pressure outside the housing 1. The second differential pressure gauge 63 continues to supply explosion-proof gas EP until two hours have elapsed since the pressure in the internal space of the housing 1 reached the first pressure. The flow rate of explosion-proof gas EP introduced into the internal space of the housing 1 and the length of the above second hour can be appropriately set to optimal values ​​based on the volume of the internal space of the housing 1, etc.

[0088] As described above, the propagation space TS of the propagation unit 7 is filled with purge gas PG, which prevents the measurement light L from being absorbed and its intensity reduced as it propagates through the propagation space TS. Furthermore, by filling the internal space of the housing 1 with explosion-proof gas EP and the propagation space TS of the propagation unit 7 with purge gas PG, explosion-proof measures for the analytical device 100 can be properly implemented. In other words, purge gas PG also serves as explosion-proof gas EP.

[0089] While maintaining the supply of purge gas PG, the explosion-proof gas EP is supplied for two hours after the pressure inside the housing 1 reaches the first pressure. When it is confirmed that the pressure inside the sampling space SS is lower than a predetermined pressure which is lower than the pressure inside the housing 1, the control unit 11 starts supplying power to the light sources 51a to 51d of the irradiation unit 5 and the detection unit 75 located in the propagation space TS, while maintaining the supply of purge gas PG and explosion-proof gas EP. This enables the analysis of the target gas by the analyzer 100.

[0090] When the analysis device 100 enables the analysis of the target gas, the sample gas SG is supplied to the sampling space SS of the filling unit 3, filling the sampling space SS with the sample gas SG. While maintaining the supply of sample gas SG to the sampling space SS, the control unit 11 controls the light sources 51a to 51d to output measurement light L toward the sampling space SS of the filling unit 3. The calculation unit 11a receives the detection signal of the measurement light L that has passed through the sampling space SS from the detection unit 75, and calculates the intensity in the wavelength range of each element light L1 to L4 of the detected measurement light L based on the detection signal.

[0091] Subsequently, the calculation unit 11a calculates the concentration of the target gas contained in the sample gas SG based on the ratio of the intensity of the measurement light L before passing through the sampling space SS filled with the sample gas SG and the intensity of the measurement light L after passing through the sampling space SS filled with the sample gas SG.

[0092] For example, if the gas to be measured can absorb all of the elemental light beams L1 to L4, the calculation unit 11a calculates the concentration of the interfering gas that interferes with the analysis result of the gas to be measured based on the intensity of each elemental light beam L1 to L4, and can accurately calculate the concentration of the gas to be measured by taking into account the influence of this interfering gas.

[0093] In addition, if there are multiple gases to be measured, the calculation unit 11a can calculate the concentration of the gas to be measured based on the intensity of any of the elemental light L1 to L4 that the gas to be measured can absorb.

[0094] In the analytical apparatus 100 described above, purge gas PG is introduced only into the propagation space TS, which is the optical path of the measurement light L. As shown in Figure 1 and other figures, the propagation space TS is a small space in volume compared to the internal space of the housing 1, so the amount of purge gas PG that needs to be introduced into the optical path of the measurement light L can be reduced.

[0095] On the other hand, a different explosion-proof gas, EP, is introduced into the large-capacity internal space of the enclosure 1. Since explosion-proof gas EP is inexpensive and suitable for explosion-proof measures, explosion-proof measures for the internal space of enclosure 1 can be implemented inexpensively and appropriately. In addition, by introducing explosion-proof gas EP into the internal space of enclosure 1, the various components housed inside the enclosure 1 can be cooled.

[0096] Furthermore, by providing a partition plate 9 in the internal space of the housing 1, the internal space of the housing 1 is separated into a first internal space IS1 in which the irradiation unit 5 and propagation unit 7 are located, and a second internal space IS2 in which the filling unit is located. This allows the irradiation unit 5 and propagation unit 7 to be spatially separated from the filling unit 3, which becomes hot. As a result, the explosion-proof gas EP in the first internal space IS1 is not heated by the hot filling unit 3, so the irradiation unit 5 and propagation unit 7 can be cooled efficiently.

[0097] Furthermore, the measurement light L used for analyzing the target gas is guided through a propagation space TS filled with purge gas PG to a filled section 3 filled with sample gas SG. This prevents the measurement light L from being absorbed in the propagation space TS before reaching the filled section 3. As a result, the target gas contained in the sample gas SG can be analyzed with high accuracy using the measurement light L.

[0098] 2. Other Embodiments Although several embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention. In particular, the multiple embodiments and modifications described herein can be arbitrarily combined as needed. (A) In the analytical apparatus 100, the propagation space TS is provided with a first mirror 71a, a second mirror 71b, a third mirror 71c, a fourth mirror 71d, a fifth mirror 71e, and a sixth mirror 71f. The arrangement of these mirrors may be changed depending on the positional relationship between the light sources 51a to 51d and the filling section 3 inside the housing 1.

[0099] For example, if the distance between the light sources 51a to 51d and the filling section 3 decreases as the distance between them decreases, the distance from the light sources 51a to 51d to the filling section 3 through which the measurement light L propagates in the propagation space TS may be reduced, or mirrors may not be provided in the propagation space TS.

[0100] (B) When the analysis device 100 generates purge gas PG by the separation unit 41, the deterioration of the separation unit 41 may be determined. This determination can be made, for example, by outputting measurement light L with the propagation space TS and / or sampling space SS filled with purge gas PG generated from the separation unit 41, measuring the intensity of the measurement light L after it has passed through the propagation space TS and / or sampling space SS with the detection unit 75, and determining the degree of deterioration of the separation unit 41 based on how much the measured intensity of the measurement light L has decreased from the original intensity.

[0101] (C) For example, if the supply device 21 is supplied with a gas that does not contain components unsuitable for explosion protection, such as instrumentation air, the separation unit 41 can be placed inside the housing 1, and the remaining gas other than the purge gas PG from the components separated by the separation unit 41 from the gas supplied from the supply device 21 can be used as the explosion-proof gas EP.

[0102] Specifically, as shown in Figure 5, the separation unit 41 is placed inside the housing 1, the exhaust port for the remaining gas from the separation unit 41 is used as the inlet IN1 of the explosion-proof gas introduction unit 20, and the exhaust port for the purge gas PG is used as the inlet IN2 of the purge gas introduction unit 40. Figure 5 shows another example of the gas flow configuration of the analyzer. With this configuration, it is not necessary to provide separate gas lines for supplying the purge gas PG and for supplying the explosion-proof gas EP. [Industrial applicability]

[0103] This invention can be widely applied to analytical devices that analyze target gases contained in a sample gas. [Explanation of Symbols]

[0104] 100 Analyzer 1 cabinet IS1 1st interior space IS2 2nd internal space 3. Filling section 31 Entrance 32 Exit 33a First reflective member 33b Second reflective member SS sampling space 5. Irradiation area 51a~51d Light source L1~L4 Element Light L measurement light 7. Propagation section 71a First mirror 71b Second Mirror 71c Third Mirror 71d Fourth mirror 71e Fifth Mirror 71f 6th Mirror 73a First optical element 73b Second optical element 73c Third optical element 75 Detection unit 711 Screw TS propagation space 9 partition plates 11 Control Unit 111 Display section 13 Outlet 15 Fixed plate 20 Explosion-proof gas introduction section 21 Feeding device 40 Purge gas inlet 41 Separation part 61. First Differential Pressure Gauge P1, P2 ports 63. Second Differential Pressure Gauge P3, P4 ports 65 Pressure switch 67 Pressure gauge 80 jigs 81 Main body 83 Through hole 85 Handle GL1 No. 1 Gas Line GL2 Second Gas Line GL3 Third Gas Line GL4 No. 4 Gas Line GL5 5th Gas Line GL6 Gas Line 6 IN1~IN3 Entrance OUT~OUT3 Exit EP explosion-proof gas PG purge gas SG sample gas T-tool W Optical Window

Claims

1. An analytical device for analyzing the target gas, A filling section into which a sample gas containing the gas to be measured is filled, An irradiation unit that irradiates with measurement light used for the analysis of the target gas, A propagation unit is provided between the filling unit and the irradiation unit, forming a propagation space for propagating the measurement light irradiated from the irradiation unit to the filling unit, A housing that houses the filling section, the irradiation section, and the propagation section, A purge gas introduction unit is provided for introducing a purge gas that does not contain the gas to be measured into the propagation space, The internal space of the enclosure includes an explosion-proof gas introduction section for introducing an explosion-proof gas that does not contain highly flammable gases, An analytical device equipped with the following features.

2. The analytical apparatus according to claim 1, further comprising a partition plate that separates the internal space of the housing into a first internal space in which the irradiation unit and the propagation unit are located, and a second internal space in which the filling unit is located.

3. The analytical apparatus according to claim 1, wherein the housing and the propagation section are configured as internal pressure explosion-proof containers.

4. The analytical apparatus according to claim 1, further comprising a pressure switch for detecting whether the pressure in the filling section has become equal to or greater than a predetermined pressure that is less than the pressure in the internal space of the housing.

5. The analytical apparatus according to claim 1, further comprising a first differential pressure gauge for measuring the difference between the pressure near the outlet of the purge gas in the propagation space and the pressure in the internal space of the housing.

6. The analytical apparatus according to claim 1, further comprising a second differential pressure gauge for measuring the difference between the pressure near the outlet for the explosion-proof gas in the internal space of the housing and the pressure outside the housing.

7. The propagation unit is arranged in the propagation space and has a mirror that guides the measurement light to the filling unit. The system further includes a jig for bringing the tool for adjusting the mirror to the position of the mirror in the propagation space. The analytical apparatus according to claim 1.

8. The analytical apparatus according to claim 1, further comprising a fixing plate for fixing the filling section, the irradiation section, and the propagation section.

9. The analytical apparatus according to claim 1, further comprising a separation unit for separating the purge gas from the gas.

10. The analytical apparatus according to claim 9, wherein the separation unit is provided outside the housing.

11. The separation unit is located inside the housing. The analytical apparatus according to claim 9, wherein the remaining gas other than the purge gas from the components resulting from the separation of the gas by the separation unit is used as the explosion-proof gas.

12. A first differential pressure gauge measures the difference between the pressure near the outlet of the purge gas in the propagation space and the pressure in the internal space of the housing, A second differential pressure gauge measures the difference between the pressure near the outlet for the explosion-proof gas in the internal space of the housing and the pressure outside the housing. The system further includes a pressure switch that detects whether the pressure in the filling section has risen to or below a predetermined pressure that is less than the pressure in the internal space of the housing, The analytical apparatus according to claim 1, wherein the first differential pressure gauge, the second differential pressure gauge, and the pressure switch measure the relationship between the pressure inside the housing and the pressure outside the housing, the relationship between the pressure inside the propagation space and the pressure inside the housing, the relationship between the pressure inside the propagation space and the pressure inside the filling section, and the relationship between the pressure inside the housing and the pressure inside the filling section.

13. The analytical apparatus according to claim 1, wherein the target gas for measurement is carbon dioxide, carbon monoxide, methane, sulfur dioxide, ammonia, nitrogen oxides, hydrogen chloride, water, ethane, acetylene, propane, ethylene, hexane, propylene, hydrogen sulfide, isobutene, methanol, phosgene, butane, chloroethylene, methyl nitrite, cyclohexane, butadiene, isobutane, isopentane, toluene, hydrogen, hydrogen fluoride, and trifluoropropene.

14. A method for analyzing a target gas using an analytical apparatus comprising: a filling section filled with a sample gas containing the target gas; an irradiation section that irradiates the target gas with measurement light used for analysis; a propagation section provided between the filling section and the irradiation section, forming a propagation space for propagating the measurement light irradiated from the irradiation section to the filling section; and a housing that houses the filling section, the irradiation section, and the propagation section, The steps include introducing a purge gas that does not contain the gas to be measured into the propagation space, The steps include introducing an explosion-proof gas that does not contain highly flammable gases into the internal space of the enclosure, The steps include: irradiating the measurement light from the irradiation unit and propagating the measurement light through the propagation space to the filling unit filled with the sample gas; The steps include analyzing the target gas contained in the sample gas based on the measurement results of the measurement light that has passed through the sample gas filled in the filling section, An analytical method that includes the following features.

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