Gas sensing device and photoacoustic spectroscopy gas sensor

Abstract

This invention discloses a gas sensing device and a photoacoustic spectroscopy gas sensor. The gas sensing device includes a transmitter and a photoacoustic spectroscopy gas sensor. The transmitter emits a predetermined electromagnetic wave. The photoacoustic spectroscopy gas sensor is disposed on one side of the transmitter and includes a reaction chamber, a receiving chamber, a microelectromechanical unit (MEMS), and an application-specific integrated circuit (ASIC). The reaction chamber has a reaction space for containing a gas. The predetermined electromagnetic wave can pass through the reaction chamber into the reaction space, causing the gas to react with the predetermined electromagnetic wave to generate a sound wave to be measured. The receiving chamber is connected to the reaction chamber and has a receiving space. The receiving chamber and the reaction chamber share a common acoustic channel. The MEMS is disposed within the receiving chamber and covers the acoustic channel, allowing the sound wave to be measured to be directly sensed by the MEMS. The ASIC is connected to the MEMS.

Description

Technical Field

[0001] This invention relates to a sensing device, and more particularly to a gas sensing device and a photoacoustic spectroscopy gas sensor. Background Technology

[0002] Existing gas sensing devices utilize the photoacoustic effect to detect gases. The principle behind these devices is that when a gas absorbs light energy of a specific wavelength (hereinafter referred to as the sound wave to be measured), the gas molecules undergo thermal expansion, thereby generating a sound wave. Thus, existing gas sensing devices detect the sound wave to identify the presence and concentration of the gas.

[0003] However, existing gas sensing devices have a relatively long distance between the location where the gas is irradiated and the location of the sensor. In other words, the path for the sound wave to travel to the sensor is too long, resulting in significant measurement errors and slow sensing speed. In addition, existing gas sensing devices sometimes have excessively large reaction chambers, causing a long time required for the gas to enter the reaction chamber and reach an equilibrium concentration, which also leads to significant measurement errors and slow sensing speed.

[0004] Therefore, the inventor believed that the above-mentioned defects could be improved, and thus devoted himself to research and applied scientific principles, and finally proposed an invention that is reasonably designed and effectively improves the above-mentioned defects. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a gas sensing device and a photoacoustic spectroscopy gas sensor to address the shortcomings of the prior art.

[0006] One embodiment of the present invention discloses a gas sensing device, comprising: a transmitter capable of emitting a predetermined electromagnetic wave; and a photoacoustic spectroscopy gas sensor disposed on one side of the transmitter, the photoacoustic spectroscopy gas sensor comprising: a reaction chamber having a reaction space for containing a gas, the reaction chamber being able to be penetrated by the predetermined electromagnetic wave into the reaction space, causing the gas and the predetermined electromagnetic wave to generate a sound wave to be measured; a receiving cavity connected to the reaction chamber, the receiving cavity having a receiving space, and the receiving cavity and the reaction chamber sharing a sound channel, the sound channel connecting the receiving space and the reaction space; a microelectromechanical unit (MEMS) disposed in the receiving cavity and covering the sound channel, allowing the sound wave to be measured to be directly sensed by the MEMS; and an application-specific integrated circuit (ASIC) connected to the MEMS.

[0007] Optionally, the reaction chamber includes a ring wall and a light-transmitting cover. The ring wall is disposed on the receiving chamber and is covered by the light-transmitting cover, which can be penetrated by a predetermined electromagnetic wave.

[0008] Optionally, the reaction chamber further includes an electromagnetic wave shield, and the light-transmitting cover has a predetermined area on one side facing the accommodating chamber. The predetermined area is located on the orthogonal projection path of the sound channel along a height direction, and the electromagnetic wave shield is disposed within the predetermined area.

[0009] Optionally, the electromagnetic wave shielding is projected orthogonally along the height direction onto a projection area of ​​the accommodating cavity, covering the sound channel.

[0010] Optionally, the ring wall is made of a breathable material, allowing gas to enter the reaction space.

[0011] Optionally, the gas sensing device further includes a carrier plate and a reflective cover. The reflective cover, the transmitter, and the photoacoustic spectroscopy gas sensor are disposed on the carrier plate, and the transmitter and the photoacoustic spectroscopy gas sensor are covered by the reflective cover. The predetermined electromagnetic waves emitted by the transmitter can be reflected by the reflective cover and pass through the light-transmitting cover.

[0012] Optionally, the reflector cover has an opening on the side away from the photoacoustic spectroscopy gas sensor; the gas sensing device also includes a breathable dustproof mesh that covers the opening and allows gas to enter from the outside of the reflector cover to the inside of the reflector cover.

[0013] Optionally, the gas sensing device also includes a bracket with two facing surfaces, on which an emitter and a photoacoustic spectroscopy gas sensor are respectively mounted. The predetermined electromagnetic waves emitted by the emitter can directly pass through the light-transmitting cover.

[0014] Optionally, the ring wall is made of an airtight material, and the accommodating cavity has an opening on one side away from the reaction cavity; the gas sensing device also includes a breathable dustproof mesh that covers the opening and allows gas to enter the accommodating cavity.

[0015] Optionally, the gas sensing device further includes a carrier plate and a reflective cover. The reflective cover, the transmitter, and the photoacoustic spectroscopy gas sensor are disposed on the carrier plate, and the transmitter and the photoacoustic spectroscopy gas sensor are covered by the reflective cover. The predetermined electromagnetic waves emitted by the transmitter can be reflected by the reflective cover and pass through the light-transmitting cover.

[0016] Optionally, the gas sensing device also includes a bracket with two facing surfaces, on which an emitter and a photoacoustic spectroscopy gas sensor are respectively mounted. The predetermined electromagnetic waves emitted by the emitter can directly pass through the light-transmitting cover.

[0017] Optionally, there is a minimum predetermined distance between the light-transmitting cover and the side of the receiving cavity facing the light-transmitting cover, the minimum predetermined distance being between 0.1 mm and 1 mm.

[0018] Optionally, the wavelength of the predetermined electromagnetic wave is 4.26 micrometers, and the frequency of the predetermined electromagnetic wave is between 10 Hz and 200 Hz.

[0019] Optionally, the gas sensing device further includes a carrier plate and a reflective cover, the reflective cover being disposed on the carrier plate to create a closed space, and the transmitter and photoacoustic spectroscopy gas sensor being disposed within the closed space; the surrounding wall is made of an impermeable material, the reaction space and the containment space are not connected to the closed space, the closed space can be filled with a first gas to absorb a portion of the predetermined electromagnetic waves, and the reaction space can be pre-filled with a second gas to absorb another portion of the predetermined electromagnetic waves.

[0020] Optionally, the ring wall is made of an airtight material, and the reaction space and the containment space are not connected. The support has an open space, which can be filled with a first gas to absorb a portion of the predetermined electromagnetic waves, and the reaction space can be pre-filled with a second gas to absorb another portion of the predetermined electromagnetic waves.

[0021] One embodiment of the present invention discloses a photoacoustic spectroscopy gas sensor, comprising: a reaction chamber having a reaction space for containing a gas, the reaction chamber being capable of being penetrated by a predetermined electromagnetic wave into the reaction space, causing the gas and the predetermined electromagnetic wave to generate a sound wave to be measured; a receiving cavity connected to the reaction chamber, the receiving cavity having a receiving space, and the receiving cavity and the reaction chamber sharing a sound channel, the sound channel connecting the receiving space and the reaction space; a microelectromechanical unit (MEMS) disposed within the receiving cavity and covering the sound channel, enabling the sound wave to be measured to be directly sensed by the MEMS; and an application-specific integrated circuit (ASIC) connected to the MEMS.

[0022] In summary, the gas sensing device and photoacoustic spectroscopy gas sensor disclosed in the embodiments of the present invention can measure the sound wave to be measured more in real time and more accurately through the design that "the accommodating cavity and the reaction cavity both have a sound channel, the sound channel connects the accommodating space and the reaction space" and "the microelectromechanical unit is disposed in the accommodating cavity and covers the sound channel, so that the sound wave to be measured can be directly sensed by the microelectromechanical unit".

[0023] To further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are for reference and illustration only and are not intended to limit the present invention. Attached Figure Description

[0024] Figure 1 This is a plan view of the gas sensing device according to the first embodiment of the present invention;

[0025] Figure 2This is a plan view of a gas sensing device according to a second embodiment of the present invention;

[0026] Figure 3 This is a plan view of a gas sensing device according to a third embodiment of the present invention;

[0027] Figure 4 This is a plan view of the gas sensing device according to the fourth embodiment of the present invention;

[0028] Figure 5 This is a plan view of the gas sensing device according to the fifth embodiment of the present invention;

[0029] Figure 6 This is a plan view of a gas sensing device according to the sixth embodiment of the present invention. Detailed Implementation

[0030] The following specific embodiments illustrate the implementation of the "gas sensing device and photoacoustic spectroscopy gas sensor" disclosed in this invention. Those skilled in the art can understand the advantages and effects of this invention from the content disclosed in this specification. This invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this invention. Furthermore, the accompanying drawings of this invention are for simple illustrative purposes only and are not depictions of actual dimensions; this is stated beforehand. The following embodiments will further describe the relevant technical content of this invention in detail, but the disclosed content is not intended to limit the scope of protection of this invention.

[0031] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used herein should, as appropriate, include any combination of one or more of the related listed items.

[0032] Additionally, in the following description, if it is indicated that a specific drawing is referred to or shown in a specific drawing, it is only to emphasize that most of the relevant content in the following description appears in that specific drawing, but does not limit the following description to refer only to that specific drawing.

[0033] [First Embodiment]

[0034] See Figure 1As shown in the figure, this embodiment provides a gas sensing device 100A. The gas sensing device 100A includes a carrier board 1, a transmitter 2 disposed on the carrier board 1, a photoacoustic spectroscopy gas sensor 3 disposed on the carrier board 1 and on one side of the transmitter 2, a reflection cover 4 disposed on the carrier board 1 and covering the transmitter 2 and the photoacoustic spectroscopy gas sensor 3, and a breathable and dust-proof net 5 disposed on the reflection cover 4.

[0035] It should be noted first that although the above-mentioned carrier board 1, transmitter 2, photoacoustic spectroscopy gas sensor 3, reflection cover 4 and breathable and dust-proof net 5 are jointly defined as the gas sensing device 100A in this embodiment, the present invention is not limited thereto. For example, the photoacoustic spectroscopy gas sensor 3 can also be used alone (such as implemented, manufactured, sold, etc.) or used in combination with other components. The following will introduce the respective component structures of the gas sensing device 100A and explain the connection relationships between the respective components of the gas sensing device 100A as appropriate.

[0036] Refer to Figure 1 As shown in the figure, the carrier board 1 can be a printed circuit board in this embodiment, and the carrier board 1 has two opposite wide side surfaces and an annular side surface connecting the two wide side surfaces. Among them, the carrier board 1 defines a height direction D1 and a width direction D2. The height direction D1 is the direction in which any one of the wide side surfaces faces the other wide side surface, and the width direction D2 is the extending direction of any one of the wide side surfaces, and the width direction D2 is perpendicular to the height direction D1. For the convenience of subsequent description, one of the wide side surfaces is defined as an installation surface (not labeled).

[0037] Cooperate with Figure 1 As shown in the figure, the transmitter 2 is disposed on the installation surface. The transmitter 2 can emit a predetermined electromagnetic wave to irradiate a gas, so that the gas and the predetermined electromagnetic wave generate a sound wave to be measured. The predetermined electromagnetic wave can be visible light or invisible light.

[0038] Among them, in this embodiment, the wavelength of the predetermined electromagnetic wave can be selected as 4.26 micrometers, and the frequency of the predetermined electromagnetic wave can be selected to be between 10 Hz and 200 Hz, but the present invention is not limited thereto. In practice, the wavelength and frequency of the predetermined electromagnetic wave can be adjusted according to the type of gas to be detected.

[0039] Such as Figure 1 As shown in the figure, the photoacoustic spectroscopy gas sensor 3 can accommodate the gas and receive the predetermined electromagnetic wave, so that the gas molecules of the gas generate the sound wave to be measured through thermal expansion by the predetermined electromagnetic wave. At the same time, the photoacoustic spectroscopy gas sensor 3 can perform real-time detection when the sound wave to be measured is generated.

[0040] Specifically, the photoacoustic spectroscopy gas sensor 3 includes a reaction cavity 31, a housing cavity 32, a microelectromechanical unit 33, and an application-specific integrated circuit 34. Among them, the housing cavity 32 is disposed on the mounting surface, and the reaction cavity 31 is disposed on a side surface of the housing cavity 32 away from the carrier board 1. That is to say, the reaction cavity 31 and the housing cavity 32 are stacked and arranged along the height direction D1. The housing cavity 32 has a housing space SP32, and the microelectromechanical unit 33 and the application-specific integrated circuit 34 are arranged in the housing space SP32.

[0041] In addition, the reaction cavity 31 is connected to the housing cavity 32, and the reaction cavity 31 has a reaction space SP31 for temporarily housing the gas. The reaction cavity 31 can be penetrated by the predetermined electromagnetic wave into the reaction space SP31, so that the gas and the predetermined electromagnetic wave generate the acoustic wave to be measured.

[0042] It should be noted that the housing cavity 32 and the reaction cavity 31 jointly have a sound channel SC. That is to say, the sound channel SC connects the housing space SP32 and the reaction space SP31. The microelectromechanical unit 33 covers the sound channel SC, so that the acoustic wave to be measured can be directly sensed by the microelectromechanical unit 33.

[0043] In practice, the reaction cavity 31 includes a ring wall 311 and a light-transmitting cover 312. The ring wall 311 is made of a breathable material, and the light-transmitting cover 312 is made of a material that can be penetrated by the predetermined electromagnetic wave. The ring wall 311 is disposed on the housing cavity 32 and covered by the light-transmitting cover 312 (that is, the light-transmitting cover 312 is disposed on the ring wall 311), so that the ring wall 311 and the light-transmitting cover 312 can cooperate with the side surface of the housing cavity 32 facing the reaction cavity 31 to jointly form the reaction space SP31. That is to say, the ring wall 311 can allow the gas to enter the reaction space SP31 and wait to be irradiated by the predetermined electromagnetic wave.

[0044] Optionally, there is a minimum predetermined distance H between the light-transmitting cover 312 and the side surface of the housing cavity 32 facing the light-transmitting cover. The minimum predetermined distance H is between 0.1 mm and 1 mm, but the present invention is not limited thereto.

[0045] In addition, the light-transmitting cover 312 can include a material structure or laminate that absorbs specific wavelengths to absorb according to the wavelength of the gas.

[0046] See Figure 1As shown, the reflective cover 4 is disposed on the mounting surface of the carrier plate 1, and the reflective cover 4 can cooperate with the carrier plate 1 to form a closed space SP4. That is to say, the transmitter 2 and the photoacoustic spectroscopy gas sensor 3 are covered by the reflective cover 4 and located within the closed space SP4. The inner edge of the reflective cover 4 can reflect the predetermined electromagnetic wave emitted by the transmitter 2, so that the predetermined electromagnetic wave passes through the light-transmitting cover 312 after reflection.

[0047] However, the predetermined electromagnetic waves reflected by the reflective cover 4 may pass through the sound channel SC and irradiate the microelectromechanical unit 33, thereby causing inaccurate measurements by the photoacoustic spectroscopy gas sensor 3. Therefore, the reaction chamber 31 may also include an electromagnetic wave shield 313. Specifically, the light-transmitting cover 312 has a predetermined area (not shown) on one side facing the accommodating cavity 32, the predetermined area being located on the orthogonal projection path of the sound channel SC along the height direction D1, and the electromagnetic wave shield 313 is disposed within the predetermined area, so that the microelectromechanical unit 33 can shield the predetermined electromagnetic waves passing through the sound channel SC through the electromagnetic wave shield 313.

[0048] Optionally, the electromagnetic wave shield 313 is projected orthogonally along the height direction D1 onto a projection area of ​​the accommodating cavity 32, covering the sound channel SC. For example, the area of ​​the electromagnetic wave shield 313 is larger than the area of ​​the sound channel SC, so that the sound channel SC is covered by the electromagnetic wave shield 313 in the height direction.

[0049] Cooperate Figure 1 As shown, in this embodiment, the reflective cover 4 has an opening OP on the side of the reflective cover 4 away from the photoacoustic spectroscopy gas sensor 3 for filling the gas, and the opening OP is covered by the breathable dustproof net 5 to ensure that the gas can enter from the outside of the reflective cover 4 to the inside of the reflective cover 4.

[0050] In other words, the gas enters the reflective cover 4 through the breathable dustproof mesh 5, and then diffuses through the ring wall 311 made of breathable material to enter the reaction space SP31. Thus, when the gas in the reaction space SP31 is irradiated by the predetermined electromagnetic wave, the sound wave to be measured is generated and directly sensed by the microelectromechanical unit 33 located on the sound channel SC.

[0051] In practice, the ring wall 311 made of the breathable material can be made of a material that can block sound waves, so that the sound waves to be measured are prevented from escaping outside the photoacoustic spectroscopy gas sensor 3, or the photoacoustic spectroscopy gas sensor 3 is prevented from being interfered with by external sound waves.

[0052] It should be noted that, in this embodiment, the application-specific integrated circuit 34 is connected to the microelectromechanical unit 33, and the application-specific integrated circuit 34 can cooperate with the microelectromechanical unit 33 to realize photoacoustic spectral sensing technology. The above-mentioned technology is prior art and not the focus of this invention, and will not be elaborated upon here.

[0053] [Second Embodiment]

[0054] like Figure 2 As shown, this is another embodiment of the present invention. The gas sensing device 100B of this embodiment is similar to the gas sensing device 100A of the first embodiment. The similarities between the two embodiments will not be repeated. The main difference between this embodiment and the gas sensing device 100A is that the gas sensing device 100B of this embodiment does not have the carrier plate 1, the reflective cover 4, and the breathable dustproof net 5, and the gas sensing device 100A includes a bracket 6.

[0055] Specifically, in this embodiment, the bracket 6 is C-shaped and has two transverse portions 61 and a longitudinal portion 62 connecting the two transverse portions 61. The two transverse portions 61 are defined as two mounting surfaces (not shown) on their opposite sides, and the transmitter 2 and the photoacoustic spectroscopy gas sensor 3 are respectively mounted on these two mounting surfaces, allowing the predetermined electromagnetic wave emitted by the transmitter 2 to directly pass through the light-transmitting cover 312. In other words, in this embodiment, the predetermined electromagnetic wave passes directly through the light-transmitting cover 312.

[0056] In addition, the support 6 in this embodiment is an open space, that is, the gas passes directly through the ring wall 311 made of breathable material to enter the reaction space SP31.

[0057] [Third Embodiment]

[0058] like Figure 3As shown, this is another embodiment of the present invention. The gas sensing device 100C in this embodiment is similar to the gas sensing device 100A in the first embodiment. The similarities between the two embodiments will not be repeated. The main difference between this embodiment and the gas sensing device 100A is that the gas travels through the accommodating space SP32 first, and then through the sound channel SC into the reaction space SP31. In other words, the gas travels through the third embodiment differently from the gas in the first embodiment.

[0059] Specifically, in this embodiment, the reflective cover 4 has no openings, the annular wall 311' is made of an airtight material, and the accommodating cavity 32 has an opening OP on the side away from the reaction cavity 31 for the gas to enter. Of course, the carrier plate 1 also has a through hole PN communicating with the opening OP. Furthermore, the breathable dustproof mesh 5 covers the opening and allows the gas to enter the accommodating cavity 32. In practice, the breathable dustproof mesh 5 can be made of a material that can block sound waves, preventing the sound waves to be measured from escaping outside the photoacoustic spectroscopy gas sensor 3, or preventing the photoacoustic spectroscopy gas sensor 3 from being interfered with by external sound waves.

[0060] [Fourth Embodiment]

[0061] like Figure 4 As shown, this is another embodiment of the present invention. The gas sensing device 100D of this embodiment is similar to the gas sensing device 100C of the third embodiment. The similarities between the two embodiments will not be repeated. The main difference between this embodiment and the gas sensing device 100C is that the gas sensing device 100D of this embodiment does not have the carrier plate 1, the reflective cover 4, and the breathable dustproof net 5, and the gas sensing device 100D includes a bracket 6'.

[0062] Specifically, in this embodiment, the bracket 6' is a closed structure with two transverse portions 61 and two longitudinal portions 62 connecting the two transverse portions 61. The two transverse portions 61 are defined as two mounting surfaces on their opposite sides, and the transmitter 2 and the photoacoustic spectroscopy gas sensor 3 are respectively mounted on the two mounting surfaces, allowing the predetermined electromagnetic wave emitted by the transmitter 2 to directly pass through the light-transmitting cover 312. That is, in this embodiment, the predetermined electromagnetic wave passes directly through the light-transmitting cover 312.

[0063] [Fifth Embodiment]

[0064] like Figure 5As shown, this is another embodiment of the present invention. The gas sensing device 100E in this embodiment is similar to the gas sensing device 100A in the first embodiment. The similarities between the two embodiments will not be repeated. The main difference between this embodiment and the gas sensing device 100A is that the reaction chamber 31 is not connected to the closed space SP4 inside the reflective cover 4.

[0065] Specifically, in this embodiment, the annular wall 311' is made of an airtight material, so that the reaction space SP31 of the reaction chamber 31 is only connected to the accommodating space SP32. That is to say, the interior of the photoacoustic spectroscopy gas sensor 3 is a sealed environment. In addition, a second gas is pre-filled inside the photoacoustic spectroscopy gas sensor 3.

[0066] In practical use, the breathable dustproof net 5 can be filled into the enclosed space SP4 by a first gas passing through it. The first gas located in the enclosed space SP4 can absorb a portion of the predetermined electromagnetic wave, and the second gas located in the reaction space SP31 can absorb the remaining portion of the predetermined electromagnetic wave. Therefore, the photoacoustic spectroscopy gas sensor can determine the concentration of the second gas based on the attenuation. The first gas and the second gas can have the same or different compositions.

[0067] [Sixth Embodiment]

[0068] like Figure 6 As shown, this is another embodiment of the present invention. The gas sensing device 100F in this embodiment is similar to the gas sensing device 100B in the first embodiment. The similarities between the two embodiments will not be repeated. The main difference between this embodiment and the gas sensing device 100B is that the reaction chamber 31 is not connected to the closed space SP4 inside the reflective cover 4.

[0069] Specifically, in this embodiment, the annular wall 311' is made of an airtight material, so that the reaction space SP31 of the reaction chamber 31 is only connected to the accommodating space SP32. That is to say, the interior of the photoacoustic spectroscopy gas sensor 3 is a sealed environment. In addition, a second gas is pre-filled inside the photoacoustic spectroscopy gas sensor 3.

[0070] In practical use, the support 6 in this embodiment is an open space, so a first gas can pass through the space between the transmitter 2 and the photoacoustic spectroscopy gas sensor 3, and the first gas can absorb a portion of the predetermined electromagnetic wave, while the second gas located in the reaction space SP31 can absorb the remaining portion of the predetermined electromagnetic wave. Therefore, the photoacoustic spectroscopy gas sensor can determine the concentration of the second gas based on the attenuation. The first gas and the second gas can have the same or different components.

[0071] [Technical Effects of the Embodiments of the Invention]

[0072] In summary, the gas sensing device and photoacoustic spectroscopy gas sensor disclosed in the embodiments of the present invention can measure the sound wave to be measured more in real time and more accurately through the design that "the accommodating cavity and the reaction cavity both have a sound channel, the sound channel connects the accommodating space and the reaction space" and "the microelectromechanical unit is disposed in the accommodating cavity and covers the sound channel, so that the sound wave to be measured can be directly sensed by the microelectromechanical unit".

[0073] The above-disclosed content is only an optional and feasible embodiment of the present invention, and is not intended to limit the claims of the present invention. Therefore, all equivalent technical changes made based on the description and drawings of the present invention are included in the claims of the present invention.

Claims

1. A gas sensing device, characterized in that, The gas sensing device includes: A transmitter capable of emitting a predetermined electromagnetic wave; and A photoacoustic spectroscopy gas sensor is disposed on one side of the transmitter, the photoacoustic spectroscopy gas sensor comprising: A reaction chamber having a reaction space for containing a gas, wherein the reaction chamber can be penetrated by the predetermined electromagnetic wave into the reaction space, so that the gas and the predetermined electromagnetic wave generate a sound wave to be measured. A receiving cavity is connected to the reaction cavity. The receiving cavity has a receiving space, and the receiving cavity and the reaction cavity share a sound channel, which connects the receiving space and the reaction space. A microelectromechanical unit (MEMS) is disposed within the accommodating cavity and covers the sound channel, allowing the sound wave to be measured to be directly sensed by the MEMS; and An application-specific integrated circuit is connected to the microelectromechanical unit.

2. The gas sensing device according to claim 1, characterized in that, The reaction chamber includes a ring wall and a light-transmitting cover. The ring wall is disposed on the accommodating chamber and is covered by the light-transmitting cover, which can be penetrated by the predetermined electromagnetic wave.

3. The gas sensing device according to claim 2, characterized in that, The reaction chamber also includes an electromagnetic wave shield. The light-transmitting cover has a predetermined area on one side facing the accommodating chamber. The predetermined area is located on the orthogonal projection path of the sound channel along a height direction, and the electromagnetic wave shield is disposed within the predetermined area.

4. The gas sensing device according to claim 3, characterized in that, The electromagnetic wave shielding is projected orthogonally along the height direction onto a projection area of ​​the accommodating cavity, covering the sound channel.

5. The gas sensing device according to claim 2, characterized in that, The ring wall is made of a breathable material, allowing the gas to enter the reaction space.

6. The gas sensing device according to claim 5, characterized in that, The gas sensing device further includes a carrier plate and a reflective cover. The reflective cover, the transmitter, and the photoacoustic spectroscopy gas sensor are disposed on the carrier plate, and the transmitter and the photoacoustic spectroscopy gas sensor are covered by the reflective cover. The predetermined electromagnetic wave emitted by the transmitter can be reflected by the reflective cover and pass through the light-transmitting cover.

7. The gas sensing device according to claim 6, characterized in that, The reflective cover has an opening on the side away from the photoacoustic spectroscopy gas sensor; the gas sensing device also includes a breathable dustproof mesh that covers the opening and allows the gas to enter from the outside of the reflective cover to the inside of the reflective cover.

8. The gas sensing device according to claim 5, characterized in that, The gas sensing device also includes a bracket with two facing surfaces, on which the transmitter and the photoacoustic spectroscopy gas sensor are respectively mounted. The predetermined electromagnetic wave emitted by the transmitter can directly pass through the light-transmitting cover.

9. The gas sensing device according to claim 2, characterized in that, The ring wall is made of an airtight material, and the accommodating cavity has an opening on one side away from the reaction cavity; the gas sensing device also includes a breathable dustproof net that covers the opening and allows the gas to enter the accommodating cavity.

10. The gas sensing device according to claim 9, characterized in that, The gas sensing device further includes a carrier plate and a reflective cover. The reflective cover, the transmitter, and the photoacoustic spectroscopy gas sensor are disposed on the carrier plate, and the transmitter and the photoacoustic spectroscopy gas sensor are covered by the reflective cover. The predetermined electromagnetic wave emitted by the transmitter can be reflected by the reflective cover and pass through the light-transmitting cover.

11. The gas sensing device according to claim 9, characterized in that, The gas sensing device also includes a bracket with two facing surfaces, on which the transmitter and the photoacoustic spectroscopy gas sensor are respectively mounted. The predetermined electromagnetic wave emitted by the transmitter can directly pass through the light-transmitting cover.

12. The gas sensing device according to claim 2, characterized in that, The light-transmitting cover and the side of the accommodating cavity facing the light-transmitting cover have a minimum predetermined distance, which is between 0.1 mm and 1 mm.

13. The gas sensing device according to claim 1, characterized in that, The wavelength of the predetermined electromagnetic wave is 4.26 micrometers, and the frequency of the predetermined electromagnetic wave is between 10 Hz and 200 Hz.

14. The gas sensing device according to claim 2, characterized in that, The gas sensing device further includes a carrier plate and a reflective cover. The reflective cover is disposed on the carrier plate to form a closed space. The transmitter and the photoacoustic spectroscopy gas sensor are disposed within the closed space. The ring wall is made of an impermeable material. The reaction space and the containment space are not connected to the closed space. The closed space can be filled with a first gas to absorb a portion of the predetermined electromagnetic wave. The reaction space can be pre-filled with a second gas to absorb another portion of the predetermined electromagnetic wave.

15. The gas sensing device according to claim 8, characterized in that, The ring wall is made of an airtight material. The reaction space and the accommodating space are not connected. The support has an open space. The open space can be filled with a first gas to absorb a portion of the predetermined electromagnetic waves. The reaction space can be pre-filled with a second gas to absorb another portion of the predetermined electromagnetic waves.

16. A photoacoustic spectroscopy gas sensor, characterized in that, The photoacoustic spectroscopy gas sensor includes: A reaction chamber having a reaction space for containing a gas, the reaction chamber being able to be penetrated by a predetermined electromagnetic wave into the reaction space, so that the gas and the predetermined electromagnetic wave generate a sound wave to be measured. A receiving cavity is connected to the reaction cavity. The receiving cavity has a receiving space, and the receiving cavity and the reaction cavity share a sound channel, which connects the receiving space and the reaction space. A microelectromechanical unit (MEMS) is disposed within the accommodating cavity and covers the sound channel, allowing the sound wave to be measured to be directly sensed by the MEMS; and An application-specific integrated circuit is connected to the microelectromechanical unit.

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