Methane sensor explosion-proof module and handheld gas detection equipment

Abstract

The embodiment of the invention discloses a methane sensor explosion-proof module and handheld gas detection equipment. The methane sensor explosion-proof module comprises an explosion-proof shell, and a breathable fire-proof piece, a methane sensor and a sensor circuit board which are arranged in the explosion-proof shell; the explosion-proof shell is provided with a gas detection port, the gas detection port is sealed by the breathable fire insulation part, the methane sensor is arranged beside the breathable fire insulation part, the gas sensing end of the methane sensor faces the breathable fire insulation part, and the sensor circuit board is arranged beside the methane sensor and is electrically connected with the methane sensor; the methane sensor adopts the combustion reaction principle, the flame-proof shell is filled with glue after being provided with the breathable fire insulation part, the methane sensor and the sensor circuit board, and the breathable fire insulation part comprises a micropore structure, so that the flame-proof function is realized while methane detection is realized by adopting the combustion reaction principle; the technical problem that an existing methane sensor adopting the combustion reaction principle lacks flame-proof measures is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of gas detection, and in particular to an explosion-proof module for a methane sensor and a handheld gas detection device. Background Art

[0002] Natural gas is dangerous. Once it leaks, if no timely measures are taken, serious consequences such as fire, explosion, and poisoning of personnel are likely to occur. Therefore, it is very necessary to detect gas leakage of natural gas and the like.

[0003] Since the main component of natural gas is methane, a handheld gas detection device with a methane sensor can be used for detecting natural gas leakage.

[0004] However, in current handheld gas detection devices, the methane sensors used are usually based on the electrochemical principle and have disadvantages such as high cost. Methane sensors based on the combustion reaction principle cannot be applied to handheld gas detection devices due to the lack of explosion-proof measures.

[0005] Therefore, there is an urgent need for a handheld gas detection device based on a methane sensor using the combustion reaction principle. Summary of the Invention

[0006] In view of at least one aspect of the above technical problems, an embodiment of the present application provides an explosion-proof module for a methane sensor and a handheld gas detection device. The explosion-proof module for a methane sensor includes an explosion-proof housing and a gas-permeable and fire-proof member, a methane sensor, and a sensor circuit board disposed inside the explosion-proof housing. A gas detection port is provided at a first end of the explosion-proof housing along a first direction, and a second end is closed. The gas-permeable and fire-proof member closes the gas detection port. Then, the methane sensor is disposed beside the gas-permeable and fire-proof member with its gas sensing end facing the gas-permeable and fire-proof member, and the sensor circuit board is disposed beside the methane sensor and electrically connected to the methane sensor. Wherein, the methane sensor adopts the combustion reaction principle. After installing the gas-permeable and fire-proof member, the methane sensor, and the sensor circuit board, the explosion-proof housing is filled with glue. And the gas-permeable and fire-proof member includes a microporous structure for external gas to pass through. Thus, the gas outside the explosion-proof housing can pass through the gas detection port and through the microporous structure to contact the gas sensing end of the methane sensor through the gas-permeable and fire-proof member. In this way, while realizing methane detection using the combustion reaction principle, the explosion-proof module for a methane sensor has an explosion-proof function, solving the technical problem that the existing methane sensor using the combustion reaction principle lacks explosion-proof measures.

[0007] In a first aspect, an embodiment of the present application provides an explosion-proof module for a methane sensor, including: An explosion-proof housing extending along a first direction, a gas detection port is provided at a first end of the explosion-proof housing along the first direction, a second end is closed, and an accommodation space is formed inside the explosion-proof housing; A breathable fire separation member is installed in the accommodation space and closes the gas detection port; A methane sensor is installed in the accommodation space and is disposed beside the breathable fire separation member, and the gas sensing end of the methane sensor is arranged facing the breathable fire separation member; A sensor circuit board is installed in the accommodation space and is disposed beside the methane sensor, and the sensor circuit board is electrically connected to the methane sensor; Wherein, the methane sensor adopts the combustion reaction principle; After installing the breathable fire separation member, the methane sensor and the sensor circuit board, the accommodation space is filled with glue; The breathable fire separation member includes a microporous structure, so that the gas outside the explosion-proof housing diffuses from the gas detection port and through the microporous structure through the breathable fire separation member to the gas sensing end.

[0008] In one embodiment, preferably, the inner wall of the explosion-proof housing is provided with internal threads, and the end of the first end of the explosion-proof housing is provided with a radially inwardly extending abutting flange, and the abutting flange extends along the circumferential direction of the explosion-proof housing to form the gas detection port; Wherein, the surface of the abutting flange facing the breathable fire separation member protrudes with an abutting boss, and along the circumferential direction of the explosion-proof housing, the abutting boss is circumferentially closed; the breathable fire separation member is in a columnar shape extending along the first direction, and the end face of the breathable fire separation member facing the abutting flange is provided with an inwardly concave groove, and the depth of the groove is the same as the height of the abutting boss, so that the groove abuts against the abutting boss.

[0009] In one embodiment, preferably, the circumferential side wall of one end of the breathable fire separation member facing the methane sensor is formed with a stepped structure by radially inwardly shrinking.

[0010] In one embodiment, preferably, the aperture of the microporous structure is between 150 and 220 microns; Wherein, the breathable fire separation member is a sintered metal block sintered from stainless steel particles by powder metallurgy, or the breathable fire separation member is a multi-layer metal mesh formed by extruding a plurality of metal meshes stacked in a staggered manner by an extrusion molding process.

[0011] In one embodiment, preferably, the explosion-proof housing includes a detachable explosion-proof column body and an explosion-proof cover body; Wherein, the first end of the explosion-proof column body along the first direction is provided with the gas detection port, the second end of the explosion-proof column body along the first direction is open, and the explosion-proof cover body is used for fixedly installing at the second end of the explosion-proof column body; Wherein, an installation ear is provided outside the first end of the flameproof column body, and the installation ear is used for being firmly installed on the main control circuit board of the handheld gas detection device. The flameproof cover body is provided with a glue filling port for filling the glue. Moreover, the flameproof cover body is provided with an abutting column for extending into the flameproof column body, and the abutting column is used for abutting against the methane sensor, so that after the flameproof cover body is fixedly installed on the second end of the flameproof column body, there is abutting between the abutting column and the methane sensor, between the methane sensor and the air-permeable and fire-separating member, and between the air-permeable and fire-separating member and the abutting flange forming the gas detection port respectively.

[0012] In one embodiment, preferably, a plurality of insertion columns protrude from the surface of the sensor circuit board facing the flameproof cover body. Wherein, the insertion columns are used for the pins of the methane sensor to be inserted from the side of the sensor circuit board facing away from the insertion columns, so that the sensor circuit board is electrically connected to the methane sensor. Moreover, after the flameproof cover body is fixedly installed on the flameproof column body, the top end of the insertion column is used for abutting against the flameproof cover body.

[0013] In one embodiment, preferably, a signal isolation sheet is provided between the methane sensor and the sensor circuit board. The signal isolation sheet is provided with a through hole for the pin to pass through, and the signal isolation board includes a transparent plastic sheet.

[0014] In a second aspect, an embodiment of the present application provides a handheld gas detection device, including a device housing and a main control circuit board installed inside the device housing. Wherein, at least a first sensor module is installed on the main control circuit board, and the first sensor module is the above-mentioned methane sensor explosion-proof module. Wherein, the device housing includes a front cover and a rear cover that are butt-jointed and installed in a first direction. Wherein, the methane sensor explosion-proof module is firmly installed on the main control circuit board through the installation ear, and the gas detection port of the methane sensor explosion-proof module faces the front cover. The front cover is provided with a first gas channel at the projection position corresponding to the gas detection port. Moreover, the rear cover is provided with a plug-in slot for the explosion-proof housing of the methane sensor explosion-proof module to be plugged in.

[0015] In one embodiment, preferably, one or more second sensor modules are further installed on the first surface of the main control circuit board facing the front cover. Any one of the second sensor modules is one of a hydrogen sulfide sensor, a carbon monoxide sensor, and an oxygen sensor that adopt the electrochemical principle. Among them, the sensing end face of the second sensor module faces the front cover, and the front cover is provided with a second gas channel at the projection position corresponding to the sensing end face; Moreover, the height of the sensing end face and the gas detection port relative to the main control circuit board is the same.

[0016] In one embodiment, preferably, three of the second sensor modules are mounted on the first surface. The three second sensor modules are the hydrogen sulfide sensor, the carbon monoxide sensor, and the oxygen sensor respectively. The three second sensor modules and the methane sensor explosion-proof module are arranged in a square; Among them, the device housing includes a calibration mask clamped to the front cover, and the calibration mask is used to cover the first gas channel and the three second gas channels at the same time; Among them, the calibration mask is provided with an inflation hole at the center position corresponding to the square. The inner surface of the calibration mask facing the front cover is provided with four abutting ribs. The abutting ribs are used to abut against the surface of the front cover when the calibration mask is clamped to the front cover. The four abutting ribs surround the inflation hole circumferentially and are evenly distributed, so as to form an air outlet channel between adjacent abutting ribs. Moreover, the four air outlet channels correspond to the three second sensor modules and the methane sensor explosion-proof module respectively.

[0017] In one embodiment, preferably, a potting seal is mounted on the second surface of the main control circuit board facing the rear cover, and the potting seal is circumferentially closed relative to the first direction; Among them, several fuses are provided on the second surface in the area surrounded by the potting seal; Moreover, the groove surrounded by the potting seal is used for filling heat-insulating glue.

[0018] In one embodiment, preferably, a screen module is mounted on the first surface of the main control circuit board facing the front cover, and the front cover is provided with a screen glass at the projection position corresponding to the screen module.

[0019] In one embodiment, preferably, the device housing includes a front panel detachably mounted on the front cover, and the front panel is used to be mounted on the surface of the front cover facing away from the rear cover; Among them, the front cover is provided with operation buttons, the front panel is provided with button openings at the projection positions corresponding to the operation buttons, and the front panel is provided with screen openings at the projection positions corresponding to the screen glass.

[0020] In one embodiment, preferably, a buzzer module is mounted on the first surface, the buzzer module is coated with a waterproof and breathable membrane, the front panel is provided with a plurality of first sound outlet through holes at the projection position corresponding to the buzzer module, the front cover is provided with a plurality of second sound outlet through holes at the projection position corresponding to the buzzer module, and the first sound outlet through holes and the second sound outlet through holes are arranged in a staggered manner with respect to the first direction.

[0021] In one embodiment, preferably, a connecting rib is formed between adjacent second sound outlet through holes, and the projection area of the connecting rib along the first direction completely covers the first sound outlet through hole.

[0022] In one embodiment, preferably, a battery module is provided between the main control circuit board and the rear cover, and the battery module is electrically connected to the main control circuit board.

[0023] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: The embodiments of the present application provide a methane sensor explosion-proof module and a handheld gas detection device.

[0024] The methane sensor explosion-proof module includes an explosion-proof housing extending along a first direction. A gas detection port is provided at a first end of the explosion-proof housing, and a second end of the explosion-proof housing is closed. An air-permeable and fire-separating member, a methane sensor, and a sensor circuit board are sequentially installed inside the explosion-proof housing from the gas detection port; wherein, the air-permeable and fire-separating member closes the gas detection port, a gas sensing end of the methane sensor faces the air-permeable and fire-separating member, and the sensor circuit board is electrically connected to the methane sensor; and, after installing the above-mentioned air-permeable and fire-separating member, methane sensor, and sensor circuit board, the internal accommodation space of the explosion-proof housing is filled with glue. The air-permeable and fire-separating member includes a microporous structure that can breathe and separate fire, and the methane sensor adopts a combustion reaction principle.

[0025] Thus, it can be understood that: On the one hand, the gas outside the explosion-proof housing can enter through the gas detection port and pass through the microporous structure of the air-permeable and fire-separating member to contact the gas sensing end of the methane sensor, realizing the detection of methane. On the other hand, considering that the methane sensor adopts a combustion reaction principle, the microporous structure of the air-permeable and fire-separating member can isolate the burning flame while breathing, preventing it from spreading to the outside of the explosion-proof housing and realizing the explosion-proof function. On the third hand, the remaining space inside the explosion-proof housing is also filled with glue, which makes the gas passing through the air-permeable and fire-separating member only contact the gas sensing end of the methane sensor, rather than filling the internal accommodation space of the explosion-proof housing, enhancing the explosion-proof function.

[0026] In other words, in view of the technical problem that existing methane sensors using the combustion reaction principle cannot be applied to handheld gas detection devices due to the lack of explosion-proof measures, this embodiment provides a methane sensor explosion-proof module with a better explosion-proof function, thus solving the above technical problem; in this way, by installing the methane sensor explosion-proof module of this embodiment in a handheld gas detection device, a handheld gas detection device based on a methane sensor using the combustion reaction principle can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments of the present invention will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0028] Figure 1 It is a schematic explosion structure diagram of the methane sensor explosion-proof module described in the embodiment of the present application.

[0029] Figure 2 It is a schematic cross-sectional structure diagram of the methane sensor explosion-proof module described in the embodiment of the present application.

[0030] Figure 3 It is a schematic explosion structure diagram of the handheld gas detection device described in the embodiment of the present application.

[0031] Figure 4 It is a schematic structure diagram of the main control circuit board described in the embodiment of the present application.

[0032] Figure 5 It is a schematic structure diagram of the handheld gas detection device described in the embodiment of the present application.

[0033] Figure 6 It is a schematic installation diagram of the calibration mask and the front cover described in the embodiment of the present application.

[0034] Figure 7 It is a schematic structure diagram of the inner surface of the calibration mask described in the embodiment of the present application, where Figure 7 the dashed line with an arrow indicates the air outlet channel.

[0035] Figure 8 It is a schematic structure diagram of the potting seal installed on the main control circuit board described in the embodiment of the present application.

[0036] Figure 9 It is a schematic assembly structure diagram of the front panel and the front cover described in the embodiment of the present application.

[0037] Figure 10 It is a partial schematic diagram at the sound outlet hole of the buzzer described in the embodiment of the present application.

[0038] Figure 11 This is a schematic diagram of the structure in which the first sound outlet through hole and the second sound outlet through hole in the embodiment of the present application are arranged in a staggered manner. Among them, Figure 11 The dotted line with an arrow indicates the water flow impact direction.

[0039] Among them, reference numerals: 10 - Flameproof housing, 11 - Gas detection port, 12 - Internal thread, 13 - Abutted flange, 14 - Abutted boss, 15 - Flameproof column, 16 - Flameproof cover, 17 - Mounting ear, 18 - Glue filling port, 19 - Notch, 161 - Abutted column, 20 - Breathable and fireproof part, 21 - Groove, 22 - Step structure, 30 - Methane sensor, 31 - Gas sensing end, 32 - Pin, 33 - Platinum wire, 40 - Sensor circuit board, 41 - Conductive part, 42 - Plug-in column, 50 - Glue, 60 - Signal isolation sheet, 61 - Perforation, 70 - First sensor module, 71 - First gas channel, 80 - Second sensor module, 81 - Second gas channel, 91 - Main control circuit board, 92 - Front cover, 93 - Rear cover, 94 - Screen module, 95 - Battery module, 96 - Calibration mask, 97 - Front panel, 98 - Buzzer module, 99 - Light guide column, 100 - Duckbill clip, 101 - typeC board, 911 - First surface, 912 - Second surface, 913 - Fuse, 914 - Glue filling and sealing part, 921 - Screen glass, 922 - Operation button, 923 - Second sound outlet through hole, 924 - Connecting rib, 931 - Plug-in slot, 961 - Inflation hole, 962 - Abutted rib, 963 - Air outlet channel, 964 - Inflation hose, 971 - Screen opening, 972 - Button opening, 973 - First sound outlet through hole, 981 - Waterproof and breathable membrane, 982 - Buzzer sound outlet hole, X - First direction. Detailed implementation manners

[0040] In order to better understand the above technical solutions, the exemplary embodiments of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. It should be understood that the present application is not limited by the exemplary embodiments described herein.

[0041] Figure 1 It is a schematic diagram of the explosion structure of the flameproof module of the methane sensor. Figure 2 It is a schematic sectional structure diagram of the flameproof module of the methane sensor. Please refer to Figure 1 and Figure 2 In the first embodiment of the present application, a flameproof module for a methane sensor is provided. The flameproof module for the methane sensor includes a flameproof housing 10, a breathable and fireproof member 20, a methane sensor 30, and a sensor circuit board 40.

[0042] The flameproof housing 10 extends along the first direction X. A gas detection port 11 is provided at the first end of the flameproof housing 10 along the first direction X, and the second end is closed. An accommodation space is formed inside the flameproof housing 10; the breathable and fireproof member 20 is installed in the accommodation space and closes the gas detection port 11; the methane sensor 30 is installed in the accommodation space and is disposed beside the breathable and fireproof member 20, and the gas sensing end 31 of the methane sensor 30 faces the breathable and fireproof member 20; the sensor circuit board 40 is installed in the accommodation space and is disposed beside the methane sensor 30. The sensor circuit board 40 is electrically connected to the methane sensor 30, and the sensor circuit board 40 is electrically connected to a conductive member 41. The conductive member 41 extends out from the second end of the flameproof housing 10 and is used for electrical connection to the main control circuit board 91 of the handheld gas detection device.

[0043] Among them, the methane sensor 30 adopts the combustion reaction principle; the accommodation space is filled with glue 50 after installing the breathable and fireproof member 20, the methane sensor 30, and the sensor circuit board 40; the breathable and fireproof member 20 includes a microporous structure, so that the gas outside the flameproof housing 10 diffuses from the gas detection port 11 and passes through the microporous structure through the breathable and fireproof member 20 to the gas sensing end 31.

[0044] That is, overall, in this embodiment, a flameproof module for a methane sensor with a flameproof function and based on the combustion reaction principle is provided by installing a breathable and fireproof member, a methane sensor, and a sensor circuit board inside the flameproof housing.

[0045] Specifically, the flameproof housing of this embodiment extends along the first direction. The flameproof housing is, for example, in the shape of a cylinder extending along the first direction. An accommodation space extending along the first direction is formed inside the flameproof housing. Moreover, a gas detection port is provided at the first end of the flameproof housing along the first direction, and the second end of the flameproof housing along the first direction is closed; that is, it can be understood that the gas outside the flameproof housing can enter the accommodation space inside the flameproof housing through the gas detection port.

[0046] Among them, a breathable and fireproof member is provided in the accommodation space inside the flameproof housing, and the breathable and fireproof member closes the gas detection port.

[0047] It can be understood that the closed gas detection port mentioned here in this embodiment should be understood as that the gas-permeable fireproof member blocks the gas detection port, and since the gas-permeable fireproof member includes a microporous structure that allows gas to pass through; in this way, the gas outside the explosion-proof housing can enter the interior of the explosion-proof housing from the gas detection port and through this microporous structure; in other words, the meaning of the gas-permeable fireproof member closing the gas detection port here is that the external gas can only pass through the microporous structure of the gas-permeable fireproof member from the gas detection port, and there is no other channel to enter the interior of the explosion-proof housing; for example, the gas-permeable fireproof member can be installed at the gas detection port by means of snap connection or nesting, or, as described in detail below, the gas-permeable fireproof member can directly abut against the abutting flange forming the gas detection port.

[0048] Among them, a methane sensor is also provided in the accommodation space inside the explosion-proof housing, and the methane sensor is arranged beside the above-mentioned gas-permeable fireproof member; the methane sensor in this embodiment is based on the combustion reaction principle, and among them, the gas sensing end of the methane sensor is arranged facing the gas-permeable fireproof member.

[0049] It can be understood that the gas sensing end of the methane sensor using the combustion reaction principle is usually provided with a platinum wire 33. After the external methane gas (that is, the methane gas outside the explosion-proof housing) diffuses from the gas detection port through the gas-permeable fireproof member to the gas sensing end and contacts the platinum wire, it will be catalytically combusted, and then heat is released. In this process, the methane sensor precisely measures this heat change, so as to accurately calculate the concentration of methane.

[0050] Among them, a sensor circuit board is also provided in the accommodation space inside the explosion-proof housing, and the sensor circuit board is arranged beside the above-mentioned methane sensor and is electrically connected to the methane sensor.

[0051] It can be understood that the sensor circuit board is electrically connected to the methane sensor, so that the sensor circuit board can receive the above-mentioned electrical signal about the heat change sensed by the methane sensor. Among them, the electrical signal can be, for example, a voltage signal or a current signal, etc.; then, the sensor circuit board can calculate the concentration of methane based on the change of this electrical signal; furthermore, the sensor circuit board then transmits the data information of the methane concentration to the main control circuit board of the handheld gas detection device.

[0052] Specifically, the sensor circuit board can be electrically connected to a conductive member, and the conductive member extends out from the second end of the explosion-proof housing and is electrically connected to the main control circuit board of the handheld gas detection device.

[0053] It can be seen that inside the explosion-proof housing, in this embodiment, a gas-permeable fireproof member, a methane sensor, and a sensor circuit board are sequentially arranged from the gas detection port, and the structural layout is reasonable.

[0054] Among them, it should be understood that the gas outside the explosion-proof housing can only diffuse into the interior of the explosion-proof housing from the gas detection port and through the microporous structure of the breathable and fireproof component. Moreover, since the gas sensing end of the methane sensor is arranged adjacent to the breathable and fireproof component, the sensitivity of the methane sensor is improved.

[0055] Among them, it should also be understood that while the microporous structure of the breathable and fireproof component allows air to pass through, considering the staggered distribution of the microporous structure, it can also prevent the flame burning at the methane sensor from spreading to the outside of the explosion-proof housing, achieving an explosion-proof effect. And, in this embodiment, after installing the breathable and fireproof component, the methane sensor, and the sensor circuit board in the accommodating space, glue is filled. It can be understood that glue with better fluidity can fill the remaining accommodating space to prevent the gas outside the explosion-proof housing from diffusing into the accommodating space through the breathable and fireproof component, enhancing the explosion-proof function.

[0056] Regarding the explosion-proof housing 10, in a possible implementation, an internal thread 12 is provided on the inner wall of the explosion-proof housing 10, and a radially inwardly extending abutting flange 13 is provided at the end of the first end of the explosion-proof housing 10. The abutting flange 13 extends along the circumferential direction of the explosion-proof housing 10 to form a gas detection port 11. Among them, an abutting boss 14 protrudes from the surface of the abutting flange 13 facing the breathable and fireproof component 20. Along the circumferential direction of the explosion-proof housing 10, the abutting boss 14 is circumferentially closed. The breathable and fireproof component 20 is in the shape of a column extending along the first direction X. An inwardly concave groove 21 is provided on the end face of the breathable and fireproof component 20 facing the abutting flange 13. The depth of the groove 21 is the same as the height of the abutting boss 14, so that the groove 21 abuts against the abutting boss 14.

[0057] That is, on the one hand, an internal thread is provided on the inner wall of the explosion-proof housing in this embodiment. Thus, it can be understood that after the explosion-proof housing is filled with glue and the glue cures to form a colloid, the setting of the internal thread can increase the contact area between the inner wall of the explosion-proof housing and the colloid, preventing the cured colloid from falling off. In addition, the setting of the internal thread also increases the explosion-proof path.

[0058] On the other hand, a radially inwardly extending abutting flange is provided at the end of the first end (i.e., the end with the gas detection port) of the explosion-proof housing in this embodiment. The abutting flange extends circumferentially in a ring shape. Thus, it can be understood that the middle area of the abutting flange forms the above-mentioned gas detection port.

[0059] Among them, referring to Figure 2 , the abutting flange is specifically abutted against the end of the breathable and fireproof component. In this way, as mentioned above, the breathable and fireproof component can close the gas detection port in the middle area of the abutting flange.

[0060] Moreover, when filling glue into the flameproof housing, in order to prevent the glue from leaking out, a contact boss protrudes from the surface of the contact flange facing the air-permeable and fire-separating member. The contact boss is arranged in a closed manner along the circumferential direction of the flameproof housing, for example, in a circular ring shape. In the projection area corresponding to the contact boss, the end face of the air-permeable and fire-separating member facing the contact flange is provided with a concave groove, for example, a circular groove. The depth of the groove should be the same as the height of the contact boss. In this way, it can be understood that when the end of the air-permeable and fire-separating member abuts against the contact flange, a stepped structure can be formed through the abutment of the contact boss and the groove, thereby preventing the flowing glue from leaking out from the gap where the air-permeable and fire-separating member is connected to the contact flange.

[0061] In a specific embodiment, a stepped structure 22 is formed on the circumferential side wall of the end of the air-permeable and fire-separating member 20 facing the methane sensor 30 by radially shrinking.

[0062] Combined with Figure 1 and Figure 2 , that is, the radius of the circumferential side wall of the end of the air-permeable and fire-separating member facing the methane sensor is smaller than the radius of the circumferential side wall of the main body of the air-permeable and fire-separating member. Thus, an inwardly shrinking stepped structure is formed at the end of the air-permeable and fire-separating member close to the methane sensor. It can be understood that in this way, the inwardly shrinking stepped structure can not only increase the contact area between the air-permeable and fire-separating member and the filled glue, but also increase the overall flameproof path. Here, the flameproof path can be understood as the contact path between the filled glue and the air-permeable and fire-separating member along the direction from the inside to the outside. Furthermore, when the flameproof path, dispensing length, etc. meet the requirements, it can achieve the effect of reducing the thickness (i.e., the dimension along the first direction) of the air-permeable and fire-separating member.

[0063] Regarding the microporous structure, in a possible embodiment, the pore diameter of the microporous structure is between 150 and 220 microns. Among them, the air-permeable and fire-separating member 20 is a sintered metal block formed by sintering stainless steel particles through a powder metallurgy process, or the air-permeable and fire-separating member 20 is a multi-layer metal mesh formed by extruding a plurality of misaligned stacked metal meshes through an extrusion molding process.

[0064] That is, to ensure that the air-permeable and fire-separating member has a better air permeability and fire separation effect, the pore diameter of the microporous structure in this embodiment is between 150 and 220 microns, preferably 170 - 190 microns.

[0065] Among them, the air-permeable and fire-separating member can be a sintered metal block, that is, the air-permeable and fire-separating member is formed by sintering stainless steel particles through a powder metallurgy process; or the air-permeable and fire-separating member can also be an extruded multi-layer metal mesh, that is, the air-permeable and fire-separating member is formed by extruding a plurality of misaligned stacked metal meshes through an extrusion molding process. This embodiment does not limit this, as long as the air-permeable and fire-separating member can achieve a better air permeability and fire separation effect.

[0066] In a possible implementation, the flameproof housing 10 includes a detachable flameproof cylinder 15 and a flameproof cover 16; wherein, a gas detection port 11 is provided at the first end of the flameproof cylinder 15 along the first direction X, the second end of the flameproof cylinder 15 is open, and the flameproof cover 16 is used for fixedly installing at the second end of the flameproof cylinder 15; wherein, an installation ear 17 is provided outside the first end of the flameproof cylinder 15, and the installation ear 17 is used for tightly installing on the main control circuit board 91 of the handheld gas detection device, and the flameproof cover 16 is provided with a glue filling port 18 for filling glue 50 and a notch 19 for the conductive part 41 to extend out; and, the flameproof cover 16 is provided with a contact post 161 for extending into the flameproof cylinder 15, and the contact post 161 is used for contacting with the methane sensor 30, so that after the flameproof cover 16 is fixedly installed at the second end of the flameproof cylinder 15, the contact post 161 and the methane sensor 30, the methane sensor 30 and the air-permeable and fireproof part 20, and the air-permeable and fireproof part 20 and the contact flange 13 forming the gas detection port are in contact respectively.

[0067] In this embodiment, to facilitate the installation of the above-mentioned air-permeable and fireproof part, methane sensor and sensor circuit board, the flameproof housing includes a detachable flameproof cylinder and a flameproof cover.

[0068] Wherein, one end of the flameproof cylinder is provided with a gas detection port through a contact flange, and the other end is open for fixedly installing the flameproof cover through, for example, screws.

[0069] To facilitate the installation of the methane sensor explosion-proof module, in this embodiment, an installation ear can be specifically provided outside the first end of the flameproof cylinder. In this way, the installation ear can be tightly fixed on the main control circuit board of the handheld gas detection device through screws.

[0070] To facilitate the filling of glue and the extension of the conductive part, in this embodiment, a glue filling port and a notch can be specifically provided on the flameproof cover. The glue filling port is used for filling glue after the flameproof cover and the flameproof cylinder are tightly installed, and the notch is used for the conductive part of the sensor circuit board to extend out after the flameproof cover and the flameproof cylinder are tightly installed.

[0071] And, the flameproof cover of this embodiment is further provided with a contact post for extending into the flameproof cylinder. It can be understood that after the flameproof cover is fixedly installed at the second end of the flameproof cylinder, the contact post can extend into the flameproof cylinder and contact with the methane sensor, so that the air-permeable and fireproof part is contacted with the contact flange forming the gas detection port through the methane sensor; that is to say, when the flameproof cover is installed, by the extrusion of the contact post on the flameproof cover, in this embodiment, the methane sensor, the air-permeable and fireproof part and the contact flange at the end of the flameproof cylinder can be extruded together to prevent the methane sensor, the air-permeable and fireproof part, etc. from shaking, and the structure is simple.

[0072] In a specific embodiment, a plurality of insertion posts 42 protrude from the surface of the sensor circuit board 40 facing the explosion-proof cover body 16; wherein, the insertion posts 42 are for the pins 32 of the methane sensor 30 to be inserted from the side of the sensor circuit board 40 facing away from the insertion posts 42, so that the sensor circuit board 40 is electrically connected to the methane sensor 30; and, after the explosion-proof cover body 16 is fixedly installed on the explosion-proof column body 15, the top end of the insertion post 42 is for abutting against the explosion-proof cover body 16.

[0073] Regarding the installation of the sensor circuit board, in this embodiment, a plurality of insertion posts protrude from the surface of the sensor circuit board facing the explosion-proof cover body. It can be understood that the plurality of insertion posts should correspond one by one to the plurality of pins of the methane sensor. Thus, on the one hand, the pins of the methane sensor can be inserted into the insertion posts from the side of the sensor circuit board facing away from the insertion posts, realizing the electrical connection between the methane sensor and the sensor circuit board. On the other hand, the insertion posts are also used to abut against the explosion-proof cover body after being tightly installed, preventing the sensor circuit board from shaking.

[0074] In another specific embodiment, a signal isolation sheet 60 is provided between the methane sensor 30 and the sensor circuit board 40. The signal isolation sheet 60 is provided with a through hole 61 for the pin 32 to pass through; wherein, the signal isolation board 60 includes a transparent plastic sheet; thus, the signal isolation sheet can play a role in signal isolation between the sensor circuit board and the methane sensor, preventing signal interference from affecting the calculation accuracy of methane.

[0075] Figure 3 For the explosion structure schematic diagram of the handheld gas detection device, please refer to Figure 3 In the second embodiment of the present application, a handheld gas detection device is provided. The handheld gas detection device includes a device housing and a main control circuit board 91 installed inside the device housing; wherein, at least a first sensor module 70 is installed on the main control circuit board 91, and the first sensor module 70 is the above-mentioned methane sensor explosion-proof module.

[0076] It can be understood that referring to the above description, since the methane sensor explosion-proof module has an explosion-proof function and can be separately explosion-proof certified, thus, the methane sensor explosion-proof module can be directly applied to different handheld gas detection devices, saving certification costs.

[0077] In a possible implementation manner, the device housing includes a front cover 92 and a rear cover 93 that are butt-joined and installed in the first direction X; wherein, the methane sensor explosion-proof module is tightly installed on the main control circuit board 91 through the mounting ear 17, and the gas detection port 11 of the methane sensor explosion-proof module faces the front cover 92. The front cover 92 is provided with a first gas channel 71 at the projection position corresponding to the gas detection port 11; and, the rear cover 93 is provided with a plug-in groove 931 for the explosion-proof housing 10 of the methane sensor explosion-proof module to be inserted.

[0078] In this embodiment, the gas detection ports of the screen module and the methane sensor flameproof module are arranged on the same side of the main control circuit board, which is convenient for use.

[0079] Among them, the methane sensor flameproof module is specifically fastened to the main control circuit board through the mounting ear at one end of the gas detection port. At this time, considering the stability of the installation of the methane sensor flameproof module, this embodiment also provides a plug-in slot for the flameproof housing to be inserted in the rear cover to increase the installation stability.

[0080] In a possible implementation manner, a screen module 94 is installed on the first surface 911 of the main control circuit board 91 facing the front cover 92, and a screen glass 921 is provided on the front cover 92 at the projection position corresponding to the screen module 94.

[0081] In a possible implementation manner, a battery module 95 is provided between the main control circuit board 91 and the rear cover 93, and the battery module 95 is electrically connected to the main control circuit board 91.

[0082] Considering that the flameproof housing extends in the first direction and has a certain height, this embodiment can use the space between the main control circuit board and the rear cover to set the battery module, that is, a battery module that avoids the methane sensor flameproof module is provided between the main control circuit board and the rear cover, realizing a reasonable layout, thereby reducing the thickness of the handheld gas detection device.

[0083] In addition, a duckbill clip 100 can be installed on the rear cover 93 for convenient use; a typceC board 101 can be provided inside the device housing for convenient charging of the battery module. Combined Figure 5 , a light guide column 99 can be provided on the front cover 92.

[0084] It can be understood that the main control circuit board 91 can simultaneously install a buzzer module 98 and a vibration motor (not shown in the figure). The main control circuit board is electrically connected to the light guide column. In this way, when the handheld gas detection device detects a dangerous gas, it can drive the light guide column, buzzer module and vibration motor to work together to remind of danger.

[0085] In a possible implementation manner, one or more second sensor modules 80 are also installed on the first surface 911. Any one of the second sensor modules 80 is one of a hydrogen sulfide sensor, a carbon monoxide sensor, and an oxygen sensor that adopts the electrochemical principle; among them, the sensing end face of the second sensor module 80 faces the front cover 92, and a second gas channel 81 is provided on the front cover 92 at the projection position corresponding to the sensing end face; and, the sensing end face and the gas detection port 11 are at the same height relative to the main control circuit board 91.

[0086] That is, to achieve the detection of multiple gases, one or more second sensor modules can be installed on the main control circuit board in this embodiment. Among them, the second sensor module adopts the electrochemical principle and can be directly installed on the main control circuit board by plugging in with pin pins without the need for explosion-proof settings.

[0087] Specifically, according to actual needs, any one of the second sensor modules can be one of a hydrogen sulfide sensor, a carbon monoxide sensor, and an oxygen sensor.

[0088] Moreover, the sensing end face of the second sensor module should be in the same plane as the gas detection port of the explosion-proof module of the methane sensor. Or rather, the sensing end face of the second sensor module should have the same height relative to the main control circuit board as the gas detection port of the explosion-proof module of the methane sensor. In this way, the explosion-proof module of the methane sensor and the second sensor module can be calibrated uniformly to ensure the detection accuracy for different gases.

[0089] In a specific embodiment, three second sensor modules 80 are installed on the first surface 911. The three second sensor modules 80 are a hydrogen sulfide sensor, a carbon monoxide sensor, and an oxygen sensor respectively. The three second sensor modules 80 and the explosion-proof module of the methane sensor are arranged in a square. Among them, the device housing includes a calibration mask 96 clamped to the front cover 92. The calibration mask 96 is used to cover the first gas channel 71 and the three second gas channels 81 at the same time. Among them, the calibration mask 96 is provided with an inflation hole 961 at the center position corresponding to the square. The inner surface of the calibration mask 96 facing the front cover 92 is provided with four abutting ribs 962. The abutting ribs 962 are used to abut against the surface of the front cover 92 when the calibration mask 96 is clamped to the front cover 92. The four abutting ribs 962 surround the inflation hole 961 circumferentially and are evenly distributed so as to form an air outlet channel 963 between adjacent abutting ribs 962. Moreover, the four air outlet channels 963 correspond to the three second sensor modules 80 and the explosion-proof module of the methane sensor respectively.

[0090] That is, according to the actual needs of multiple gas detection, the handheld gas detection device in this embodiment can be installed with a hydrogen sulfide sensor, a carbon monoxide sensor, an oxygen sensor, and an explosion-proof module of the above methane sensor at the same time. Among them, the four sensor modules (i.e., three second sensor modules and one explosion-proof module of the methane sensor) can be specifically arranged in a square.

[0091] In addition, combined with Figure 6 and Figure 7, considering the need for regular calibration of the sensor module in the handheld gas detection device, a calibration mask can also be installed on the front cover of this embodiment. Specifically, the calibration mask can be snap - connected to the front cover, for example, which makes the installation and disassembly more convenient. And when the calibration mask is snap - connected to the front cover, it should cover at least one first gas channel and three second gas channels simultaneously to ensure that all four sensor modules can pick up the calibration gas.

[0092] Specifically, the calibration mask should be provided with an inflation hole at the center position corresponding to the above - mentioned square. The inflation hole is connected to an inflation hose, and the other end of the inflation hose is connected to a calibration gas cylinder. To ensure the accuracy of calibration, it can be understood that the calibration gas should diffuse into each gas channel simultaneously and evenly from the inflation hole. For this purpose, four abutting ribs are provided on the inner surface of the calibration mask facing the front cover. The four abutting ribs surround the inflation hole circumferentially and are evenly distributed. In this way, when the calibration mask is snap - connected to the front cover, the abutting ribs abut against the surface of the front cover. Thus, an air outlet channel can be formed between adjacent abutting ribs, that is, four air outlet channels of the same size are formed, and each air outlet channel corresponds to a sensor module.

[0093] In a possible implementation manner, a potting seal 914 is installed on the second surface 912 of the main control circuit board 91 facing the rear cover 93. The potting seal 914 is circumferentially closed relative to the first direction X. Among them, several fuses 913 are provided in the area surrounded by the potting seal 914 on the second surface 912. And the groove formed by the potting seal 914 is used for filling heat - insulating glue.

[0094] It can be understood that considering the intrinsically safe design of the handheld gas detection device, it is usually necessary to set several fuses on the main control circuit board to limit the current of the circuit of the main control circuit board.

[0095] See Figure 8 , in this embodiment, several fuses of the main control circuit board are specifically surrounded by a potting seal, and then heat - insulating glue can be filled in the groove formed by the potting seal. In this way, there is only one potting seal and one potting operation, reducing costs. Among them, in this embodiment, the thickness of the heat - insulating glue should be more than 3 mm higher than the fuses.

[0096] In addition, combined with the above description, considering the space between the main control circuit board and the rear cover due to the certain height of the flame - proof housing, this embodiment can specifically set the potting seal and the fuses on the second surface of the main control circuit board facing the rear cover, which helps to reduce the thickness of the handheld gas detection device.

[0097] In a possible implementation manner, the device housing includes a front panel 97 detachably installed on the front cover 92, and the front panel 97 is used to be installed on the surface of the front cover 92 facing away from the rear cover 93; wherein, the front cover 92 is provided with operation buttons 922, the front panel 97 is provided with button openings 972 at the projection positions corresponding to the operation buttons 922, and the front panel 97 is provided with screen openings 971 at the projection positions corresponding to the screen glass 921.

[0098] In a possible implementation manner, a buzzer module 98 is installed on the first surface 911, the buzzer module 98 is coated with a waterproof and breathable membrane 981, the front panel 97 is provided with a plurality of first sound outlet through holes 973 at the projection positions corresponding to the buzzer module 98, the front cover 92 is provided with a plurality of second sound outlet through holes 923 at the projection positions corresponding to the buzzer module 98, and, the first sound outlet through holes 973 and the second sound outlet through holes 923 are arranged in a staggered manner with respect to the first direction X.

[0099] That is, on the one hand, considering factors such as the manufacturing cost, operation difficulty, and overall yield of the device housing, in this embodiment, a screen glass, operation buttons, etc. are specifically arranged on the front cover. Among them, the screen glass and the front cover can be sealed with back glue, and the operation buttons and the front cover can be sealed with TPU (thermoplastic polyurethane elastomer), and it is easy to achieve waterproof sealing; at this time, the front panel detachably installed on the front cover only serves as a decorative function, that is, the front panel is provided with screen openings at the projection positions corresponding to the screen glass, and button openings at the projection positions corresponding to the operation buttons.

[0100] On the other hand, at the projection positions corresponding to the buzzer module, in this embodiment, the waterproof treatment of the buzzer module can be realized by the staggered arrangement of the first sound outlet through holes on the front panel and the second sound outlet through holes on the front cover, that is, the first sound outlet through holes 973 and the second sound outlet through holes 923 together form a buzzer sound outlet hole 982.

[0101] Specifically, a buzzer module is installed on the first surface of the main control circuit board. Since the buzzer module itself has no waterproof ability, it is necessary to coat a waterproof and breathable membrane on the surface of the buzzer module to achieve both waterproofing and ensuring the sound output effect at the same time; considering that the impact resistance of the waterproof and breathable membrane itself is relatively poor, especially during the IPX6 level waterproof test, the waterproof and breathable membrane is easily broken by the water flow, resulting in waterproof failure.

[0102] Therefore, at the projection positions corresponding to the buzzer module, in this embodiment, a plurality of first sound outlet through holes are provided on the front panel, a plurality of second sound outlet through holes are provided on the front cover, and the first sound outlet through holes and the second sound outlet through holes are arranged in a staggered manner with respect to the first direction. It can be understood that in this way, the impact force on the waterproof and breathable membrane when the water flow impacts can be reduced or greatly reduced, improving the waterproof ability.

[0103] In a specific embodiment, a connecting rib 924 is formed between adjacent second sound outlet through-holes 923; wherein, the projection area of the connecting rib 924 along the first direction X completely covers the first sound outlet through-hole 973.

[0104] Please refer to Figure 11 , during impact, the water flow will first pass through the external first sound outlet through-hole and then through the internal second sound outlet through-hole; and in this embodiment, the connecting rib between adjacent second sound outlet through-holes completely covers the projection position of the first sound outlet through-hole, or rather, the projection of the first sound outlet through-hole along the first direction is completely located within the connecting rib; at this time, it can be understood that after passing through the first sound outlet through-hole, the water flow will all directly impact the connecting rib between adjacent second sound outlet through-holes, so that the water flow passing through the connecting rib will then pass through the second sound outlet through-hole and impact the waterproof and breathable membrane, greatly reducing the impact force and improving the waterproof ability of the waterproof and breathable membrane.

[0105] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, benefits, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, benefits, effects, etc. are essential for each embodiment of the present application. Additionally, the specific details disclosed above are only for illustrative and facilitating understanding purposes, rather than limitations, and the above details do not limit the present application to necessarily adopt the above specific details for implementation.

[0106] The block diagrams of the devices, apparatuses, equipment, and systems involved in the present application are only illustrative examples and do not intend to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open-ended terms, meaning "including but not limited to", and can be used interchangeably with each other. The words "or" and "and" used herein refer to the word "and / or" and can be used interchangeably with each other, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to" and can be used interchangeably with each other.

[0107] It also needs to be pointed out that in the devices, equipment, and methods of the present application, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present application.

[0108] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0109] The above description has been given for purposes of illustration and description. In addition, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous example aspects and embodiments have been discussed above, those skilled in the art will recognize that some of their variations, modifications, alterations, additions, and subcombinations should be included within the scope of the present invention.

Claims

1. A methane sensor explosion-proof module, characterized in that: include: A flameproof shell extends along a first direction, a first end of the flameproof shell along the first direction is provided with a gas detection port, a second end is closed, and an accommodating space is formed inside the flameproof shell; A gas-permeable fire-proof member installed in the accommodating space and sealing the gas detection port; A methane sensor is installed in the accommodating space and beside the air-permeable fire-isolating member, wherein the gas sensing end of the methane sensor is arranged toward the air-permeable fire-isolating member; A sensor circuit board is installed in the accommodating space and arranged beside the methane sensor, and the sensor circuit board is electrically connected to the methane sensor; Wherein, the methane sensor adopts the combustion reaction principle; The accommodating space is filled with glue after the air-permeable fireproof member, the methane sensor and the sensor circuit board are installed; The air-permeable fireproof member comprises a microporous structure, so that the gas outside the flameproof housing diffuses from the gas detection port through the microporous structure and through the air-permeable fireproof member to the gas sensing end.

2. The methane sensor explosion-proof module according to claim 1, characterized in that: The inner wall of the flameproof shell is provided with an internal thread, and the end of the first end of the flameproof shell is provided with a radially inwardly extending abutment flange, and the abutment flange extends along the circumferential direction of the flameproof shell to form the gas detection port; Among them, an abutment boss is protruding from the surface of the abutment flange toward the breathable fireproof member, and the abutment boss is circumferentially closed along the circumferential direction of the explosion-proof shell; the breathable fireproof member is columnar extending along the first direction, and an inwardly concave groove is provided on the end surface of the breathable fireproof member facing the abutment flange, and the depth of the groove is consistent with the height of the abutment boss, so that the groove abuts against the abutment boss; the circumferential side wall of the breathable fireproof member facing one end of the methane sensor is formed with a step structure by radially shrinking.

3. The methane sensor explosion-proof module according to claim 1, characterized in that: The pore size of the microporous structure is between 150 and 220 microns; The air-permeable fireproof member is a sintered metal block formed by sintering stainless steel particles through a powder metallurgy process, or the air-permeable fireproof member is a multi-layer metal mesh formed by extruding a plurality of staggered stacked metal meshes through an extrusion molding process.

4. The methane sensor explosion-proof module according to claim 1, characterized in that: The flameproof housing comprises a detachably mounted flameproof column and a flameproof cover; The gas detection port is provided at the first end of the flameproof column along the first direction, the second end of the flameproof column along the first direction is open, and the flameproof cover is used to be fixedly installed on the second end of the flameproof column; Wherein, a mounting ear is provided on the outside of the first end of the flameproof column, and the mounting ear is used to fasten the main control circuit board installed on the handheld gas detection device, and the flameproof cover is provided with a glue filling port for filling the glue; In addition, the explosion-proof cover body is provided with an abutment column for extending into the explosion-proof column, and the abutment column is used to abut the methane sensor, so that after the explosion-proof cover body is fixedly installed on the second end of the explosion-proof column, the abutment column and the methane sensor, the methane sensor and the air-permeable fireproof component, and the air-permeable fireproof component and the abutment flange forming the gas detection port are respectively abutted.

5. The methane sensor explosion-proof module according to claim 4, characterized in that: The sensor circuit board has a plurality of plug-in posts protruding from the surface facing the flameproof cover; The plug-in column is used for inserting the pin of the methane sensor from the side of the sensor circuit board facing away from the plug-in column, so that the sensor circuit board is electrically connected to the methane sensor; Furthermore, after the flameproof cover is fixedly installed on the flameproof column, the top end of the plug-in column is used to abut against the flameproof cover; a signal isolation plate is provided between the methane sensor and the sensor circuit board, the signal isolation plate is provided with a through hole for the pin to pass through, and the signal isolation plate includes a transparent plastic sheet.

6. A handheld gas detection device, characterized in that: It comprises a device housing and a main control circuit board installed inside the device housing; wherein at least a first sensor module is installed on the main control circuit board, and the first sensor module is a methane sensor explosion-proof module as described in any one of claims 1 to 5; Wherein, the device housing comprises a front cover and a rear cover that are butt-jointed and installed along a first direction; The methane sensor explosion-proof module is fastened to the main control circuit board through mounting ears, and the gas detection port of the methane sensor explosion-proof module is arranged toward the front cover, and the front cover is provided with a first gas channel at a projection position corresponding to the gas detection port; In addition, the rear cover is provided with a plug-in slot for plugging in the flameproof housing of the methane sensor flameproof module.

7. The handheld gas detection device according to claim 6, characterized in that: One or more second sensor modules are also installed on the first surface of the main control circuit board facing the front cover, and any one of the second sensor modules is one of a hydrogen sulfide sensor, a carbon monoxide sensor and an oxygen sensor using an electrochemical principle; Wherein, the sensing end face of the second sensor module is arranged toward the front cover, and the front cover is provided with a second gas channel at a projection position corresponding to the sensing end face; Furthermore, the sensing end surface and the gas detection port are at the same height relative to the main control circuit board.

8. The handheld gas detection device according to claim 7, characterized in that: The first surface is installed with three second sensor modules, the three second sensor modules are respectively the hydrogen sulfide sensor, the carbon monoxide sensor and the oxygen sensor, and the three second sensor modules and the methane sensor explosion-proof module are arranged in a square; Wherein, the device housing comprises a calibration mask snapped onto the front cover, and the calibration mask is used to simultaneously cover the first gas channel and three of the second gas channels; Among them, the calibration mask is provided with an inflation hole at the center position corresponding to the square, and the calibration mask is provided with four abutment ribs on the inner surface facing the front cover, and the abutment ribs are used to abut against the surface of the front cover when the calibration mask is clamped on the front cover. The four abutment ribs circumferentially surround the inflation hole and are evenly distributed to form an air outlet channel between adjacent abutment ribs, and the four air outlet channels correspond to the three second sensor modules and the methane sensor explosion-proof modules respectively.

9. The handheld gas detection device according to claim 6, characterized in that: A glue-filled seal is installed on the second surface of the main control circuit board facing the rear cover, and the glue-filled seal is circumferentially closed relative to the first direction; Wherein, the second surface is provided with a plurality of fuses in the area surrounded by the glue-filled seal; Furthermore, the groove surrounded by the glue-filling seal is used for filling the heat-insulating glue.

10. The handheld gas detection device according to claim 6, characterized in that: A screen module is installed on the first surface of the main control circuit board facing the front cover, and a screen glass is provided on the front cover at a projection position corresponding to the screen module; The device housing comprises a front panel detachably mounted to the front cover, wherein the front panel is used to be mounted on a surface of the front cover facing away from the rear cover; Wherein, the front cover is provided with an operation button, the front panel is provided with a button opening at a projection position corresponding to the operation button, and the front panel is provided with a screen opening at a projection position corresponding to the screen glass; Wherein, a buzzer module is installed on the first surface, and the buzzer module is covered with a waterproof breathable membrane, the front panel is provided with a plurality of first sound output through holes at a projection position corresponding to the buzzer module, the front cover is provided with a plurality of second sound output through holes at a projection position corresponding to the buzzer module, and the first sound output through holes and the second sound output through holes are staggered relative to the first direction; and connecting ribs are formed between adjacent second sound output through holes, and the projection area of ​​the connecting ribs along the first direction completely covers the first sound output through holes; A battery module is arranged between the main control circuit board and the rear cover, and the battery module is electrically connected to the main control circuit board.

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