Gas detection device
The gas detection device aligns the retroreflector's center with the optical axis using a beam splitter and scatterer, enhancing detection sensitivity and accuracy by aligning the optical axes and reducing false detections.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KK TOSHIBA
- Filing Date
- 2022-03-18
- Publication Date
- 2026-06-02
AI Technical Summary
Existing gas detection devices face challenges in aligning the center of the retroreflector with the optical axis of irradiated infrared rays, making it difficult to efficiently reflect and detect infrared light.
The device incorporates a beam splitter that transmits and reflects infrared and visible light, a low-pass filter to align optical axes, and a scatterer to facilitate visual alignment of the retroreflector, along with detection units to distinguish between gas absorption and light source malfunctions.
This configuration allows for easy alignment of the retroreflector's center with the optical axis, improving detection sensitivity and analysis accuracy by ensuring efficient light reflection and reducing false detections.
Smart Images
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Abstract
Description
Technical Field
[0001] Embodiments of the present invention relate to a gas detection device.
Background Art
[0002] Molecules have an absorption spectrum unique to infrared rays. Therefore, if infrared rays are irradiated onto a target space, it is possible to detect the gas present in the space and analyze the components of the gas present in the space. For example, a gas detection device having a light source provided with a space to be detected therebetween and a retroreflector has been proposed. In such a device, the center of the retroreflector and the optical axis of the irradiated infrared rays are aligned. For example, visible light coaxial with the optical axis of the irradiated infrared rays is irradiated onto the retroreflector so that the center of the retroreflector and the optical axis of the visible light coaxial with the optical axis of the infrared rays are aligned.
[0003] However, the visible light incident on the retroreflector is reflected in a direction parallel to and opposite to the incident direction. Therefore, it has been difficult for workers outside the retroreflector to visually recognize the incident position of the visible light on the retroreflector. Therefore, it has been desired to develop a gas detection device capable of easily aligning the center of the retroreflector and the optical axis of the irradiated infrared rays.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] The problem to be solved by the present invention is to provide a gas detection device capable of easily aligning the center of the retroreflector and the optical axis of the irradiated infrared rays. [Means for solving the problem]
[0006] The gas detection device according to this embodiment includes a first light source that emits infrared rays, A beam splitter that transmits and partially reflects the infrared light irradiated from the first light source, A second light source that emits visible light, and the aforementioned The beam splitter It transmits the infrared light and reflects the visible light irradiated from the second light source, and the optical axis of the visible light is The beam splitter A low-pass filter aligned with the infrared optical axis, and the aforementioned optical axis aligned The beam splitter A first retroreflector into which infrared light and visible light are incident, and the reflected light from the first retroreflector The beam splitter A first detection unit for detecting infrared rays, and the Beam splitter The system includes a fourth detection unit for detecting the infrared rays reflected by the first retroreflector, and a scattering body provided at the center of the first retroreflector. Based on the ratio of the light received signal from the first detection unit to the light received signal from the fourth detection unit, it is possible to distinguish between a decrease in the output of the first light source and absorption by gas. [Brief explanation of the drawing]
[0007] [Figure 1] This is a schematic diagram illustrating a gas detection device according to this embodiment. [Figure 2] This is a schematic diagram illustrating a gas detection device according to another embodiment. [Figure 3] This is a schematic diagram illustrating a gas detection device according to another embodiment. [Figure 4] This is a schematic diagram illustrating a gas detection device according to another embodiment. [Figure 5] This is a schematic diagram illustrating a gas detection device according to another embodiment. [Figure 6] This is a schematic diagram illustrating a gas detection device according to another embodiment. [Modes for carrying out the invention]
[0008] The embodiments will be illustrated below with reference to the drawings. In each drawing, similar components are denoted by the same reference numerals, and detailed descriptions will be omitted as appropriate. Figure 1 is a schematic diagram illustrating a gas detection device 1 according to this embodiment. As shown in Figure 1, the gas detection device 1 includes, for example, a first light source 2, a collimator lens 3, a beam splitter 4, a retroreflector 5 (corresponding to an example of the first retroreflector), a bandpass filter 6, a lens 7, a detection unit 8 (corresponding to an example of the first detection unit), a second light source 9, a lowpass filter 10, and a scatterer 11.
[0009] The first light source 2 emits light 21. The wavelength of light 21 is, for example, 0.7 μm or longer. Light 21 is, for example, infrared light. Since molecules have an inherent absorption spectrum for infrared light, irradiating gas 100 with infrared light allows for the detection of gas 100 and the analysis of its components.
[0010] The first light source 2 is, for example, a quantum cascade laser (QCL) containing a compound semiconductor. A quantum cascade laser can change its oscillation wavelength, for example, in the range of 4 μm to 16 μm. Therefore, if the first light source 2 is a quantum cascade laser, the wavelength of light 21 can be changed. For example, if the components of the gas 100 to be detected are known in advance, light 21 with a wavelength that is easily absorbed by the gas 100 can be irradiated from the first light source 2. In this way, the detection accuracy of, for example, gas leaks can be improved. For example, when analyzing the components of the gas 100 to be detected, the wavelength of light 21 irradiated onto the gas 100 can be varied. In this way, the accuracy of the analysis of the components of the gas 100 can be improved.
[0011] The collimator lens 3 is provided between the first light source 2 and the retroreflector 5. Light 21 irradiated from the first light source 2 is incident on the collimator lens 3. The collimator lens 3 makes the incident light 21 into parallel light. If the light 21 becomes parallel light, the light 21 can reach farther. Therefore, remote detection and remote analysis of the gas 100 become possible.
[0012] The beam splitter 4 is provided between the collimator lens 3 and the retroreflector 5. The beam splitter 4 transmits the light 21 that has become parallel light by the collimator lens 3. Also, the beam splitter 4 reflects the light 21 reflected by the retroreflector 5.
[0013] As will be described later, light 21 and light 91 whose optical axes are aligned by the low-pass filter 10 are incident on the retroreflector 5. The retroreflector 5 reflects the incident light 21 parallel to the incident direction and in the opposite direction. The light 21 reflected by the retroreflector 5 is incident on the beam splitter 4. The light 21 incident on the beam splitter 4 is reflected by the beam splitter 4 and incident on the detection unit 8.
[0014] The band-pass filter 6 is provided between the beam splitter 4 and the detection unit 8. Light 21 reflected by the beam splitter 4 is incident on the band-pass filter 6. The band-pass filter 6 transmits the light 21 and cuts light having a wavelength different from that of the light 21. The band-pass filter 6 is provided, for example, to suppress noise due to external disturbance light.
[0015] The lens 7 is provided between the band-pass filter 6 and the detection unit 8. The lens 7 condenses the light 21 that has passed through the band-pass filter 6. If the lens 7 is provided, the detection sensitivity and analysis accuracy of the gas 100 can be improved.
[0016] Light 21 condensed by lens 7 is incident on the detection unit 8. The detection unit 8 detects the light 21 reflected by the retroreflector 5. As described above, molecules have an absorption spectrum specific to infrared rays. Therefore, when the light 21 irradiated from the first light source 2 is incident on the gas 100, infrared rays of a predetermined wavelength are absorbed according to the components of the gas 100. Thus, by detecting the light 21 that has passed through the gas 100 and been reflected by the retroreflector 5 using the detection unit 8, the presence of the gas 100 (e.g., gas leakage) can be detected or the components of the gas 100 can be analyzed.
[0017] The detection unit 8 can be, for example, a sensor that detects infrared rays. The detection unit 8 can be, for example, an MCT sensor which is a semiconductor sensor using mercury (Hg), cadmium (Cd), and tellurium (Te).
[0018] Here, as described above, when the light 21 which is infrared rays is irradiated on the gas 100, a part of the light 21 is absorbed by the gas 100. Therefore, the amount of received light (received light signal) detected by the detection unit 8 decreases. However, even when the first light source 2 malfunctions and the amount of light 21 irradiated from the first light source 2 decreases, the amount of received light detected by the detection unit 8 also decreases. Therefore, there may be a case where it is impossible to distinguish whether the decrease in the amount of received light detected by the detection unit 8 is caused by either the gas 100 or the first light source 2.
[0019] In such a case, the first light source 2 is controlled to modulate the wavelength of the light 21 to a region outside the light absorption band of the gas 100. Then, by comparing the amount of received light in the light absorption band detected by the detection unit 8 with the amount of received light in the region outside the light absorption band, it is possible to determine whether the decrease in the amount of received light detected by the detection unit 8 is caused by either the gas 100 or the first light source 2. By doing so, false detection can be suppressed.
[0020] Furthermore, by monitoring the amount of light 21 emitted from the first light source 2 and comparing it with the amount of light received detected by the detection unit 8, it is possible to determine whether the decrease in the amount of light received detected by the detection unit 8 is due to the gas 100 or the first light source 2.
[0021] In this way, false detection can be suppressed without modulating the wavelength of light 21. The monitoring of the light intensity of the light 21 emitted from the first light source 2 will be described later (see Figure 2).
[0022] In order to improve the efficiency of light 21 reflection by the retroreflector 5, it is preferable to align the center of the retroreflector 5 with the optical axis of the parallel light 21. However, since light 21 is infrared, it tends to diverge during propagation. Therefore, in a retroreflector 5 located far from the first light source 2, the spot diameter of light 21 becomes relatively large. Also, since light 21 is infrared, it cannot be seen. Therefore, it becomes difficult to align the center of the retroreflector 5 with the optical axis of light 21.
[0023] Therefore, the gas detection device 1 is equipped with a second light source 9, a low-pass filter 10, and a scatterer 11. The second light source 9 emits light 91. Light 91 is, for example, visible light. The spot diameter of light 91 is smaller than the spot diameter of light 21. Since light 91 is visible light, it can be used as a guide light to align the center of the retroreflector 5 with the optical axis of light 21. The second light source 9 is, for example, a visible light semiconductor laser. If the second light source 9 is a visible light semiconductor laser, the light 91 with a small spot diameter can be made to travel a long distance.
[0024] The low-pass filter 10 is placed between the beam splitter 4 and the retroreflector 5. The low-pass filter 10 transmits light 21, which has a longer wavelength than light 91, and reflects light 91. Light 91, which is irradiated from the second light source 9 and reflected by the low-pass filter 10, enters the retroreflector 5. As mentioned above, light 91 is a guide light. Therefore, the optical axis of the light 91 reflected by the low-pass filter 10 is aligned with the optical axis of light 21. For example, an infrared sensor seal or the like is used to visualize the spot of light 21, and light 91 is directed to the center of the visualized spot of light 21. In this way, the optical axis of the light 91 reflected by the low-pass filter 10 can be aligned with the optical axis of light 21. In this case, the irradiation position of light 91 can be adjusted by changing the tilt angle of the low-pass filter 10. In other words, the low-pass filter 10 transmits the light 21 emitted from the first light source 2, reflects the light 91 emitted from the second light source 9, and aligns the optical axis of the light 91 with the optical axis of the light 21.
[0025] If the optical axis of light 91 aligns with the optical axis of light 21, then, for example, the position of the retroreflector 5 can be moved so that light 91 is incident on the center of the retroreflector 5. In this way, the center of the retroreflector 5 and the optical axis of light 21 can be aligned.
[0026] However, the retroreflector 5 reflects the incident light 91 in a direction parallel to and opposite to the direction of incidence. As a result, the light 91 reflected by the retroreflector 5 does not come towards the worker adjusting the position of the retroreflector 5. Consequently, it becomes difficult for the worker to visually confirm the incident position of the light 91 on the retroreflector 5, making it difficult to align the center of the retroreflector 5 with the optical axis of the light 21.
[0027] Therefore, the retroreflector 5 is provided with a scatterer 11. The scatterer 11 can be positioned so as to coincide with the center of the retroreflector 5 when viewed from the direction of incidence of the light 91. The scatterer 11 scatters the incident light 91. For example, the scatterer 11 causes Rayleigh scattering of the incident light 91. For example, the scatterer 11 can contain multiple particles smaller than the wavelength of the light 91. The particles contained in the scatterer 11 can be, for example, titanium oxide particles. The scatterer 11 can also cause diffuse reflection of the incident light 91. In this case, the scatterer 11 can be formed from, for example, paper, or contain barium sulfate.
[0028] A portion of the light 91 incident on the scatterer 11 is directed in a direction intersecting the direction of incidence of the light 91. This makes it easy for the operator to visually confirm the incident position of the light 91 on the retroreflector 5.
[0029] Furthermore, since the light 21 incident on the scatterer 11 is also scattered, the light 21 incident on the scatterer 11 cannot be detected by the detection unit 8. However, since the spot diameter of the light 91 is small, the dimensions of the scatterer 11 can be reduced. Therefore, the amount of light 21 that becomes undetectable by providing the scatterer 11 can be suppressed, and consequently, the impact on detection sensitivity and analysis accuracy can be suppressed.
[0030] As described above, with the gas detection device 1 according to this embodiment, the center of the retroreflector 5 and the optical axis of the irradiated light 21 can be easily aligned. Therefore, the light 21 incident on the retroreflector 5 can be reflected efficiently, thereby improving detection sensitivity and analysis accuracy.
[0031] Next, we will explain how to monitor the amount of light 21 emitted from the first light source 2. Figure 2 is a schematic diagram illustrating a gas detection device 1a according to another embodiment. The gas detection device 1a is the same as the gas detection device 1 described above, but with the addition of a function to monitor the amount of light 21.
[0032] As shown in Figure 2, the gas detection device 1a includes, for example, a first light source 2, a collimator lens 3, a beam splitter 4, a retroreflector 5, a bandpass filter 6, a lens 7, a detection unit 8, a second light source 9, a lowpass filter 10, a scatterer 11, a lens 12, and a detection unit 13.
[0033] As mentioned above, the beam splitter 4 transmits the light 21, which has been made parallel by the collimator lens 3. At this time, a portion of the light 21 incident on the beam splitter 4 is reflected by the beam splitter 4. Therefore, by detecting the light 21 reflected by the beam splitter 4, the light intensity of the light 21 can be monitored.
[0034] The lens 12 focuses the light 21 reflected by the beam splitter 4. The presence of the lens 12 improves the detection sensitivity and accuracy of the detection unit 13.
[0035] Light 21 focused by the lens 12 enters the detection unit 13. The detection unit 13 can be, for example, a sensor that detects infrared light. The detection unit 13 can be, for example, an MCT sensor.
[0036] The light intensity of light 21 can be monitored, for example, as follows: The ratio of the light received signal (amount of light received) from the detection unit 13 to the light received signal (amount of light received) from the detection unit 8 remains unchanged even if the amount of light 21 emitted from the first light source 2 changes, but changes when the light 21 is irradiated onto the gas 100 (when a portion of the light 21 is absorbed by the gas 100).
[0037] Therefore, it is possible to determine whether the decrease in the amount of light detected by the detection unit 8 is due to the gas 100 or the first light source 2. Furthermore, if gas detection device 1a is used, the center of the retroreflector 5 and the optical axis of the irradiated light 21 can be easily aligned, similar to gas detection device 1 described above.
[0038] Figure 3 is a schematic diagram illustrating a gas detection device 1b according to another embodiment. As shown in Figure 3, the gas detection device 1b includes, for example, a first light source 2, a collimator lens 3, a beam splitter 4, a retroreflector 5a (corresponding to an example of a second retroreflector), a bandpass filter 6, a lens 7, a detection unit 8 (corresponding to an example of a second detection unit), a second light source 9, a lowpass filter 10, and a detection unit 14 (corresponding to an example of a third detection unit).
[0039] Similar to the retroreflector 5 described above, light 21 and light 91, whose optical axes are aligned, are incident on the retroreflector 5a. The retroreflector 5a reflects the incident light 21 in a direction parallel to the direction of incidence and in the opposite direction. The detection unit 8 detects the light 21 reflected by the retroreflector 5a.
[0040] Furthermore, a hole 5a1 is provided in the center of the retroreflector 5a. A detection unit 14 is provided on the side of the retroreflector 5a opposite to the side where the light 21 is incident. Therefore, the light 91 irradiated from the second light source 9 can enter the detection unit 14 through the hole 5a1.
[0041] The detection unit 14 detects light 91 through the hole 5a1 of the retroreflector 5a. The detection unit 14 can be, for example, a sensor that detects light 91, which is visible light. A transmission unit 14a can also be connected to the detection unit 14. The transmission unit 14a transmits the received light signal from the detection unit 14 to an external device. For example, the transmission unit 14a transmits the received light signal to an external device via an optical signal or Wi-Fi (short-range wireless communication).
[0042] As mentioned above, the hole 5a1 is located at the center of the retroreflector 5a. Therefore, by adjusting the position of the retroreflector 5a based on the light signal received from the detection unit 14, the center of the retroreflector 5a can be aligned with the optical axis of the light 21.
[0043] Furthermore, for example, a moving device 18 can be provided to adjust the position of the retroreflector 5a. The moving device 18 moves the position of the retroreflector 5a relative to the light 21 and light 91 whose optical axes are aligned. For example, by providing a moving device 18 such as a two-axis robot to the retroreflector 5a and controlling the moving device 18 based on the light received signal from the detection unit 14, the center of the retroreflector 5a and the optical axis of light 91, and consequently the center of the retroreflector 5a and the optical axis of light 21 can be aligned. In this way, the center of the retroreflector 5a and the optical axis of light 21 can be aligned by automatic control.
[0044] With the gas detection device 1b according to this embodiment, the center of the retroreflector 5a and the optical axis of the irradiated light 21 can be easily aligned. Therefore, the light 21 incident on the retroreflector 5a can be reflected efficiently, thereby improving detection sensitivity and analysis accuracy.
[0045] Figure 4 is a schematic diagram illustrating a gas detection device 1c according to another embodiment. As shown in Figure 4, the gas detection device 1c includes, for example, a first light source 2, a collimator lens 3, a beam splitter 4, a retroreflector 5a, a bandpass filter 6, a lens 7, a detection unit 8, a second light source 9, a lowpass filter 10, a detection unit 14, and an irradiation position adjustment unit 15.
[0046] The irradiation position adjustment unit 15 controls the irradiation positions of the light beams 21 and 91, whose optical axes are aligned, in the retroreflector 5a. The irradiation position adjustment unit 15 includes, for example, a mirror 15a, a drive unit 15b, and a control unit 15c.
[0047] A pair of mirrors 15a may be provided. The pair of mirrors 15a are pivotably mounted. For example, one mirror 15a is provided to adjust the direction of illumination of light 21 and light 91 in the horizontal direction. The other mirror 15a is provided to adjust the direction of illumination of vertical light 21 and light 91.
[0048] The drive unit 15b changes the reflection angles of light 21 and light 91, and consequently the illumination positions of light 21 and light 91 in the retroreflector 5a, by changing the angles of the pair of mirrors 15a. The drive unit 15b may be equipped with a control motor, such as a servo motor.
[0049] The control unit 15c controls the drive unit 15b based on the light received signal from the detection unit 14 input via the transmission unit 14a. For example, the control unit 15c changes the irradiation position of light 21 and light 91 in the retroreflector 5a by changing the angle of a pair of mirrors 15a based on the light received signal from the detection unit 14.
[0050] Furthermore, a mobile device 18, such as a two-axis robot, can be added to the retroreflector 5a. In this case, the control unit 15c can align the center of the retroreflector 5a with the optical axis of the light 91, and consequently the center of the retroreflector 5a with the optical axis of the light 21, by controlling at least one of the irradiation position adjustment unit 15 and the mobile device 18.
[0051] With the gas detection device 1c according to this embodiment, the center of the retroreflector 5a and the optical axis of the light 21 can be automatically aligned. Therefore, the efficiency of the alignment work can be improved.
[0052] In the gas detection devices 1 to 1c illustrated above, a beam splitter 4 is used to guide the light 21 reflected by the retroreflector 5 (5a) to the detection unit 8. In this case, the light 21 reflected by the retroreflector 5 (5a) is parallel light, but since the light 21 is infrared, it tends to diverge during propagation. Therefore, for example, when the distance between the detection unit 8 and the retroreflector 5 (5a) is long in the optical axis direction of the light 21, the diverged light 21 can be detected by the detection unit 8. In the following description, we will explain the case of retroreflector 5 in which a scattering body 11 is provided, but the same applies to retroreflector 5a in which a detection unit 14 is provided.
[0053] Figure 5 is a schematic diagram illustrating a gas detection device 1d according to another embodiment. As shown in Figure 5, the gas detection device 1d includes, for example, a first light source 2, a collimator lens 3, a retroreflector 5, a bandpass filter 6, a lens 7, a detection unit 8, a second light source 9, a lowpass filter 10, a scatterer 11, and a mirror 16.
[0054] A portion of the light 21 reflected by the retroreflector 5 enters the mirror 16. The light 21 that enters the mirror 16 is reflected by the mirror 16. The light 21 reflected by the mirror 16 enters the detection unit 8 via the bandpass filter 6 and lens 7. In this way, beam splitter 4 can be omitted. Furthermore, if we use gas detection device 1d, similar to gas detection device 1 described above, the center of the retroreflector 5 and the optical axis of the irradiated light 21 can be easily aligned.
[0055] Figure 6 is a schematic diagram illustrating a gas detection device 1e according to another embodiment. As shown in Figure 6, the gas detection device 1e includes, for example, a first light source 2, a collimator lens 3, a retroreflector 5, a bandpass filter 6, a detection unit 8, a second light source 9, a lowpass filter 10, a scatterer 11, and a parabolic mirror 17.
[0056] The parabolic mirror 17 has a hole 17a. Light 21 emitted from the first light source 2 is made into parallel light by the collimator lens 3. The parallel light 21 is emitted onto the retroreflector 5 through the hole 17a. The light 21 reflected by the retroreflector 5 is reflected by the reflective surface 17b of the parabolic mirror 17. The light 21 is focused by being reflected by the reflective surface 17b. The focused light 21 is incident on the detection unit 8.
[0057] In this way, the beam splitter 4 and lens 7 can be omitted. Furthermore, if we use gas detection device 1e, similar to gas detection device 1 described above, the center of the retroreflector 5 and the optical axis of the irradiated light 21 can be easily aligned.
[0058] Although several embodiments of the present invention have been illustrated above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. Furthermore, the embodiments described above can be implemented in combination with each other. [Explanation of symbols]
[0059] 1 Gas detection device, 1a-1e Gas detection devices, 2 First light source, 3 Collimator lens, 4 Beam splitter, 5 Retroreflector, 5a Retroreflector, 5a1 Hole, 8 Detection unit, 9 Second light source, 10 Low-pass filter, 11 Scatterer, 13 Detection unit, 14 Detection unit, 15 Irradiation position adjustment unit, 16 Mirror, 17 Parabolic mirror, 17a Hole, 17b Reflecting surface, 18 Moving device
Claims
1. A first light source that emits infrared light, A beam splitter that transmits and partially reflects the infrared light irradiated from the first light source, A second light source that emits visible light, A low-pass filter that transmits the infrared light transmitted through the beam splitter, reflects the visible light irradiated from the second light source, and aligns the optical axis of the visible light with the optical axis of the infrared light transmitted through the beam splitter, A first retroreflector into which the infrared light and visible light transmitted through the beam splitter, whose optical axes are aligned, A first detection unit for detecting the infrared light that has been transmitted through the beam splitter reflected by the first retroreflector, A fourth detection unit for detecting the infrared light reflected by the beam splitter, A scattering body provided at the center of the first retroreflector, Equipped with, A gas detection device capable of distinguishing between a decrease in output of the first light source and absorption by gas, based on the ratio of the light received signal from the first detection unit and the light received signal from the fourth detection unit.
2. The gas detection device according to claim 1, wherein a portion of the visible light incident on the scattering body is irradiated in a direction intersecting the direction of incidence of the visible light.
3. The gas detection device according to claim 1 or 2, wherein the scattering body is provided at a position that coincides with the center of the first retroreflector when viewed from the direction of incidence of the visible light.
4. A first light source that emits infrared light, A second light source that emits visible light, A low-pass filter that transmits the infrared light emitted from the first light source, reflects the visible light emitted from the second light source, and aligns the optical axis of the visible light with the optical axis of the infrared light, The infrared and visible light, whose optical axes are aligned, are incident upon a second retroreflector having a hole in the center, A second detection unit for detecting the infrared rays reflected by the second retroreflector, A third detection unit is provided on the side of the second retroreflector opposite to the infrared incident side, and detects the visible light through the hole in the second retroreflector. A gas detection device equipped with a gas detection system.
5. The gas detection device according to claim 4, further comprising an irradiation position adjustment unit in the second retroreflector that controls the irradiation positions of the infrared light and the visible light whose optical axes are aligned.
6. The gas detection device according to claim 4 or 5, further comprising a moving device for moving the position of the second retroreflector with respect to the infrared and visible light whose optical axes are aligned.