A small-scale high-concentration VOCs gas detection method

Abstract

The present invention discloses a small-scale high-concentration VOCs gas detection method, comprising an adaptive sample gas path for providing a stable flow of a sample / sample gas to be tested for FID, an adaptive air path for providing oxygen for FID combustion, a hydrogen path for providing a stable flow of hydrogen for FID combustion, and FID; the present invention designs a new adaptive air path, so that high-concentration VOCs gas can be measured without separately providing oxygen, and the FID will not be extinguished when the concentration of the measured gas is too high, so that in actual use, there is no need to carry components such as oxygen tanks, thereby making the overall system structure simple, and miniaturized and portable through the arrangement of internal devices, and the operation is simpler. At the same time, through a closed-loop gas supply system (adaptive sample gas path, adaptive air path), the flow stability of each gas path can be ensured, and the detection accuracy is improved.

Description

Technical Field

[0001] The invention relates to the field of portable total hydrocarbon detection equipment, in particular to a high-concentration VOCs gas detection system. Background Art

[0002] During the environmental monitoring process, VOCs gases in the ambient atmosphere will be detected. In the prior art, it is necessary to detect gases in an environment with high VOCs concentrations. In addition to providing sample gas and hydrogen to the FID, the existing equipment or devices also need to provide oxygen separately to prevent the FID from flameout and failure to operate due to excessively high sample gas concentration and low oxygen content. The existing equipment needs to carry an oxygen tank, which is not only large and heavy, and inconvenient to carry, but also not conducive to the miniaturization of the instrument. At the same time, the device is relatively complex and costly, and cannot meet the portability requirements. Therefore, it is necessary to find new ways or methods to solve some or all of the problems. Summary of the invention

[0003] In view of this, this case mainly focuses on gas detection in a high-concentration VOCs environment, and it is necessary to overcome at least one of the above-mentioned defects in the prior art.

[0004] The present invention provides a small-scale high-concentration VOCs gas detection method, including an adaptive sample gas path for providing a stable flow of a sample / sample gas to be tested for FID, an adaptive air gas path for providing oxygen for FID combustion, a hydrogen gas path for providing a stable flow of hydrogen for FID combustion, and FID; The adaptive sample gas path includes a first sample gas inlet, a first filter connected to the rear side of the first sample gas inlet, a first diaphragm pump connected to the rear side of the first filter membrane, a first throttle valve connected in parallel to the rear side of the first diaphragm pump to form a three-way gas path for discharging excess gas, a first gas resistor connected to the FID at the rear side, and a first pressure sensor; The adaptive air path includes a second sample gas inlet, a second filter connected to the rear side of the second sample gas inlet, a second diaphragm pump connected to the rear side of the second filter, a second pressure sensor connected in parallel to the rear side of the second diaphragm pump to form a two-way gas path, and a second air resistor connected to the FID at the rear side; The hydrogen gas circuit includes a one-way charging valve, a high-pressure gas storage cylinder connected to the rear side of the one-way charging valve, and a diaphragm pressure regulating valve connected to the rear side of the high-pressure gas storage cylinder. The rear side of the diaphragm pressure regulating valve forms three paths, the first path is connected to the third pressure sensor, the second path is connected to the first normally closed ultramicro solenoid valve group, the first normally closed ultramicro solenoid valve group is connected to the FID, the third path is connected to the second normally closed ultramicro solenoid valve group, the rear side of the second normally closed ultramicro solenoid valve group is connected to the third gas resistance, and the rear end of the third gas resistance is connected to the FID.

[0005] According to the background technology of this patent, when detecting gas in an environment with high concentration of VOCs, the prior art also needs to provide oxygen separately to prevent the FID from flameout due to lack of oxygen. At the same time, since oxygen needs to be provided separately, it is necessary to carry an oxygen tank, which is not only large in size, heavy, and inconvenient to carry, but also not conducive to the miniaturization of the instrument. At the same time, the device is relatively complex and costly, and cannot meet the portability requirements. The present invention discloses a small-scale high-concentration VOCs gas detection method, which can measure high-concentration VOCs gas without providing oxygen separately by designing a new adaptive air path, so that when the concentration of the measured gas is too high, the FID will not flameout, so that in actual use, there is no need to carry oxygen tanks and other components, thereby making the overall system structure simple, and miniaturized and portable through the arrangement of internal devices, and the operation is simpler. At the same time, through the closed-loop gas supply system (adaptive sample gas path, adaptive air path), the flow stability of each gas path can be ensured, and the detection accuracy can be improved.

[0006] Among them, the operation mode and principle of the adaptive sample gas path: under the action of the first diaphragm pump, the sample gas passes through the first filter membrane and the first diaphragm pump in turn, and then the gas is divided into four paths, the first path flows into the FID through the first air resistance, the second path flows into the first pressure sensor, and the third path is discharged through the first throttle valve. This sampling system can discharge excess gas through the first throttle valve and obtain a stable flow of sample gas at the first air resistance; as the number of particles in the filter membrane increases, the speed of the first diaphragm pump motor is adjusted through the first pressure sensor to maintain the gas in the gas path within a stable range. This system has a simple structure and is easy to miniaturize, and the gas flow is controllable.

[0007] Adaptive air circuit operation mode and principle: Under the action of the second diaphragm pump, the measured gas (containing high concentration of non-methane total hydrocarbons) passes through the second filter and the second diaphragm pump in turn to obtain air, and then the air is divided into two paths, the first path flows into the FID through the second air resistance, and the second path flows into the second pressure sensor. This sampling system obtains a stable flow of air at the second air resistance; as the metal sintered filter element particles increase, the speed of the second diaphragm pump motor is adjusted through the second pressure sensor to maintain the gas in the air circuit within a stable range. The structure of this air filtration system is also simple and easy to miniaturize, and the gas flow is controllable.

[0008] Operation mode and principle of hydrogen gas circuit: the gas in the gas source is stored in the high-pressure gas storage cylinder through the one-way charging valve, the diaphragm pressure regulating valve is adjusted to adjust the outlet pressure to the required pressure value, and the gas is output to the first normally closed ultra-micro solenoid valve, the second normally closed ultra-micro solenoid valve, and the gas in the first normally closed ultra-micro solenoid valve is directly transmitted to the FID, and the gas in the second normally closed ultra-micro solenoid valve is transmitted to the FID after the third gas resistance is stabilized. When the FID ignites, a large amount of hydrogen is required, and the first normally closed ultra-micro solenoid valve and the second normally closed ultra-micro solenoid valve are opened at the same time; when a small amount of gas is required when the FID runs smoothly, the first normally closed ultra-micro solenoid valve is closed, the second normally closed ultra-micro solenoid valve is opened, and the second normally closed ultra-micro solenoid valve outputs a stable small flow of gas through the third gas resistance. The hydrogen gas circuit system has a simple structure and is easy to operate. The size of the gas cylinder can be adjusted according to the use requirements of the detection equipment, which is convenient for miniaturization. It is insensitive to changes in ambient temperature and pressure, and has a fast response speed. It can perform rapid gas flow conversion, and the third gas resistance can realize microfluidic and high-speed precision control through the steady flow.

[0009] Among them, in the above three gas circuit operation modes, "the gas in the gas circuit is maintained within a stable range", and this stable range can be specifically set according to specific experimental conditions.

[0010] In addition, a small-scale high-concentration VOCs gas detection method disclosed in the present invention also has the following additional technical features: Furthermore, the first filter for filtering the sample gas includes a first filter element, and the first filter element is made of a porous polytetrafluoroethylene material.

[0011] Furthermore, the porous polytetrafluoroethylene material has a pore size of 0.4-0.5 microns.

[0012] Preferably, the porous polytetrafluoroethylene material has a pore size of 0.45 microns.

[0013] Furthermore, the second filter for filtering the sample gas includes a second filter element, which is a primary filter cotton or a molecular sieve or an activated carbon or a metal sintered filter element. The second filter element can filter dust particles larger than 5μm, VOCs gas, and water vapor.

[0014] Furthermore, one end of the one-way inflation valve is directly connected to the high-pressure gas storage cylinder, and the other end is a high-pressure quick connector connected to a quick connector of a gas source.

[0015] Among them, the first diaphragm pump is responsible for collecting and transporting sample gas, and the size of sample gas flow is positively correlated with the size of current; the first throttle valve is a valve that realizes flow regulation and control by changing the size of the valve orifice; the knob on the throttle valve is adjusted to make the pressure inside the four-way gas distributor reach the set value; the air resistance is used to stabilize the outlet flow; the first and second pressure sensors are used to measure the pressure inside the sample gas path and the air path respectively, and reversely control the first and second diaphragm pumps. When the pressure decreases, the motor speed of the first and second diaphragm pumps is increased to increase the intake volume. When the pressure is higher than the set value, the motor speed of the first and second diaphragm pumps is reduced to reduce the intake volume; the diaphragm pressure regulating valve is used to adjust the cylinder gas with gradually reduced pressure to a pressure maintained within a stable range for output; the third pressure sensor is used to detect the hydrogen outlet pressure, and the normally closed ultra-micro solenoid valve realizes the opening and closing of the fluid channel through the opening and closing action, thereby controlling the flow of the fluid.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 It is a structural schematic diagram of a small-scale high-concentration VOCs gas detection method in an embodiment of the present invention; Figure 2 This is a schematic diagram of the overall appearance structure of a small-scale high-concentration VOCs gas detection method in an embodiment of the present invention; Figure 3 is a schematic diagram of the internal structure in an embodiment of the present invention; Figure 4 is a schematic diagram of the structure of the upper cover plate in an embodiment of the present invention; Figure 5 Schematic diagram of a handle in an embodiment of the present invention.

[0018] Among them, 1 adaptive sample gas circuit, 1-1 first sample gas inlet, 1-2 first filter, 1-3 first diaphragm pump, 1-4 first throttle valve, 1-5 first air resistance, 1-6 first pressure sensor, 2 adaptive air circuit, 2-1 second sample gas inlet, 2-2 second filter, 2-3 second diaphragm pump, 2-4 second pressure sensor, 2-5 second air resistance, 3 hydrogen gas circuit, 3-1 one-way charging valve, 3-2 high pressure gas storage bottle, 3-3 diaphragm pressure regulating valve, 3-4 third pressure sensor, 3-5 first normally closed ultra-micro solenoid valve, 3-6 second normally closed ultra-micro solenoid valve 3-7 third air resistance; A main housing module, A1-1 battery, A1-2 air filter, A1-3 control board PCB assembly, A1-4 gas diversion assembly, A1-5 filter, A1-6 sample gas diaphragm pump, A1-7 diaphragm pump fixed buffer rack, A1-8 air diaphragm pump, A1-9 pressure relief valve, A1-10 FID assembly, A1-11 hydrogen pressure regulating assembly, A1-12 high-pressure hydrogen storage cylinder assembly, A1-13 electromagnetic reversing valve assembly, A1-14 sample gas inlet quick plug, A1-15 lower housing A1-16 upper and lower housing sealing strips; B upper housing module, B2-1 upper housing, B2-2 display assembly, B2-3 button assembly; C handle module, C3-1 button assembly, C3-2 display assembly, C3-3 handle data transmission cable, C3-4 sample gas inlet pipe, C3-5 handle housing assembly, C3-6 filter, C3-7 sampling steel pipe. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0020] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "bottom", "top", "front", "back", "inside", "outside", "horizontal", "vertical", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "connection", "communication", "connected", "coupling" and "fitting" should be understood in a broad sense. For example, it can be a fixed connection, an integral connection, or a detachable connection; it can be the internal connection of two elements; it can be directly connected or indirectly connected through an intermediate medium; "fitting" can be the fit between surfaces, or the fit between points and surfaces or lines and surfaces, and also includes the fit between holes and axes. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] The inventive concept of the present invention is as follows: a small-scale high-concentration VOCs gas detection method is provided. By designing a new adaptive air circuit, high-concentration VOCs gas can be measured without the need to provide oxygen separately, thereby preventing the FID from being extinguished when the concentration of the measured gas is too high. In actual use, there is no need to carry components such as oxygen tanks, thereby making the overall system structure simple, and miniaturized and portable through the arrangement of internal components, making the operation easier. At the same time, through a closed-loop gas supply system (adaptive sample gas circuit, adaptive air circuit), the flow stability of each gas circuit can be ensured, thereby improving the detection accuracy.

[0023] A small-scale high-concentration VOCs gas detection method of the present invention will be described below with reference to the accompanying drawings, wherein Figure 1 It is a structural schematic diagram of a small-scale high-concentration VOCs gas detection method in an embodiment of the present invention; Figure 2 This is a schematic diagram of the overall appearance structure of a small-scale high-concentration VOCs gas detection method in an embodiment of the present invention; Figure 3 is a schematic diagram of the internal structure in an embodiment of the present invention; Figure 4 is a schematic diagram of the structure of the upper cover plate in an embodiment of the present invention; Figure 5 Schematic diagram of a handle in an embodiment of the present invention.

[0024] like Figures 1 to 4 As shown, according to an embodiment of the present invention, the small-scale high-concentration VOCs gas detection method includes an adaptive sample gas path for providing a stable flow of the measured sample / sample gas for FID, an adaptive air gas path for providing oxygen for FID combustion, a hydrogen gas path for providing a stable flow of hydrogen for FID combustion, and FID; The adaptive sample gas path includes a first sample gas inlet, a first filter connected to the rear side of the first sample gas inlet, a first diaphragm pump connected to the rear side of the first filter membrane, a first throttle valve connected in parallel to the rear side of the first diaphragm pump to form a three-way gas path for discharging excess gas, a first gas resistor connected to the FID at the rear side, and a first pressure sensor; The adaptive air path includes a second sample gas inlet, a second filter connected to the rear side of the second sample gas inlet, a second diaphragm pump connected to the rear side of the second filter, a second pressure sensor connected in parallel to the rear side of the second diaphragm pump to form a two-way gas path, and a second air resistor connected to the FID at the rear side; The hydrogen gas circuit includes a one-way charging valve, a high-pressure gas storage cylinder connected to the rear side of the one-way charging valve, and a diaphragm pressure regulating valve connected to the rear side of the high-pressure gas storage cylinder. The rear side of the diaphragm pressure regulating valve forms three paths, the first path is connected to the third pressure sensor, the second path is connected to the first normally closed ultramicro solenoid valve group, the first normally closed ultramicro solenoid valve group is connected to the FID, the third path is connected to the second normally closed ultramicro solenoid valve group, the rear side of the second normally closed ultramicro solenoid valve group is connected to the third gas resistance, and the rear end of the third gas resistance is connected to the FID.

[0025] Among them, the operation mode and principle of the adaptive sample gas path: under the action of the first diaphragm pump, the sample gas passes through the first filter membrane and the first diaphragm pump in turn, and then the gas is divided into four paths, the first path flows into the FID through the first air resistance, the second path flows into the first pressure sensor, and the third path is discharged through the first throttle valve. This sampling system can discharge excess gas through the first throttle valve and obtain a stable flow of sample gas at the first air resistance; as the number of particles in the filter membrane increases, the speed of the first diaphragm pump motor is adjusted through the first pressure sensor to maintain the gas in the gas path within a stable range. This system has a simple structure and is easy to miniaturize, and the gas flow is controllable.

[0026] Adaptive air circuit operation mode and principle: Under the action of the second diaphragm pump, the measured gas (containing high concentration of non-methane total hydrocarbons) passes through the second filter and the second diaphragm pump in turn to obtain air, and then the air is divided into two paths, the first path flows into the FID through the second air resistance, and the second path flows into the second pressure sensor. This sampling system obtains a stable flow of air at the second air resistance; as the metal sintered filter element particles increase, the speed of the second diaphragm pump motor is adjusted through the second pressure sensor to maintain the gas in the air circuit within a stable range. The structure of this air filtration system is also simple and easy to miniaturize, and the gas flow is controllable.

[0027] Operation mode and principle of hydrogen gas circuit: the gas in the gas source is stored in the high-pressure gas storage cylinder through the one-way charging valve, the diaphragm pressure regulating valve is adjusted to adjust the outlet pressure to the required pressure value, and the gas is output to the first normally closed ultra-micro solenoid valve, the second normally closed ultra-micro solenoid valve, and the gas in the first normally closed ultra-micro solenoid valve is directly transmitted to the FID, and the gas in the second normally closed ultra-micro solenoid valve is transmitted to the FID after the third gas resistance is stabilized. When the FID ignites, a large amount of hydrogen is required, and the first normally closed ultra-micro solenoid valve and the second normally closed ultra-micro solenoid valve are opened at the same time; when a small amount of gas is required when the FID runs smoothly, the first normally closed ultra-micro solenoid valve is closed, the second normally closed ultra-micro solenoid valve is opened, and the second normally closed ultra-micro solenoid valve outputs a stable small flow of gas through the third gas resistance. The hydrogen gas circuit system has a simple structure and is easy to operate. The size of the gas cylinder can be adjusted according to the use requirements of the detection equipment, which is convenient for miniaturization. It is insensitive to changes in ambient temperature and pressure, and has a fast response speed. It can perform rapid gas flow conversion, and the third gas resistance can realize microfluidic and high-speed precision control through the steady flow.

[0028] According to an embodiment of the present invention, the first filter for filtering the sample gas includes a first filter element, and the first filter element is made of porous polytetrafluoroethylene.

[0029] Furthermore, the porous polytetrafluoroethylene material has a pore size of 0.4-0.5 microns.

[0030] Preferably, the porous polytetrafluoroethylene material has a pore size of 0.45 microns.

[0031] According to an embodiment of the present invention, the second filter used to filter the sample gas includes a second filter element, which is a primary filter cotton or a molecular sieve or an activated carbon or a metal sintered filter element. The second filter element can filter dust particles larger than 5μm, VOCs gas, and water vapor.

[0032] According to an embodiment of the present invention, one end of the one-way inflation valve is directly connected to the high-pressure gas storage bottle, and the other end is a high-pressure quick connector connected to the quick connector of the gas source.

[0033] According to one embodiment of the present invention, the small-sized high-concentration VOCs gas detection system includes a main housing module consisting of an upper and lower housing, and a handle module connected to the main housing module.

[0034] Among them, the lower shell includes batteries, air filters, control board PCB components, gas diversion components, filters, sample gas diaphragm pumps, diaphragm pump fixed buffer racks, air diaphragm pumps, pressure relief valves, FID components, hydrogen pressure regulating components, high-pressure hydrogen storage cylinder components, electromagnetic reversing valve components, sample gas inlet quick-connect connectors, lower shells, upper and lower shell sealing strips, etc. The connection relationship and spatial position structure are based on the following: Figure 3As shown, in the internal design, on the one hand, relevant equipment that meets the design requirements is adopted, and on the other hand, miniaturization design is carried out according to actual needs during the design process.

[0035] At the same time, the upper shell also includes a display assembly, a button assembly, etc., which are components for human-computer interaction.

[0036] The handle module includes key components, display components, handle data transmission line, sample gas inlet pipe, handle shell components, filter, sampling steel pipe and other components. The connection relationship and spatial position structure are based on the following: Figure 5 shown.

[0037] Any reference to "one embodiment," "an embodiment," "an illustrative embodiment," etc., means that a specific component, structure, or feature described in connection with the embodiment is included in at least one embodiment of the present invention. Such illustrative expressions throughout this specification do not necessarily refer to the same embodiment. Moreover, when a specific component, structure, or feature is described in connection with any embodiment, it is claimed that it is within the scope of those skilled in the art to implement such component, structure, or feature in connection with other embodiments.

[0038] Although specific embodiments of the present invention have been described in detail with reference to a number of illustrative embodiments of the present invention, it must be understood that a variety of other modifications and embodiments may be devised by those skilled in the art that will fall within the spirit and scope of the principles of the present invention. Specifically, within the scope of the foregoing disclosure, the accompanying drawings, and the claims, reasonable variations and improvements may be made in the arrangement of components and / or dependent combinations without departing from the spirit of the present invention. Except for variations and improvements in components and / or arrangement, the scope is defined by the appended claims and their equivalents.

Claims

1. A small-scale high-concentration VOCs gas detection method, characterized in that , including an adaptive sample gas circuit for providing a stable flow of the measured sample / sample gas for FID, an adaptive air gas circuit for providing oxygen for FID combustion, a hydrogen gas circuit for providing a stable flow of hydrogen for FID combustion, and FID; The adaptive sample gas path includes a first sample gas inlet, a first filter connected to the rear side of the first sample gas inlet, a first diaphragm pump connected to the rear side of the first filter membrane, a first throttle valve connected in parallel to the rear side of the first diaphragm pump to form a three-way gas path for discharging excess gas, a first gas resistor connected to the FID at the rear side, and a first pressure sensor; The adaptive air path includes a second sample gas inlet, a second filter connected to the rear side of the second sample gas inlet, a second diaphragm pump connected to the rear side of the second filter, a second pressure sensor connected in parallel to the rear side of the second diaphragm pump to form a two-way gas path, and a second air resistor connected to the FID at the rear side; The hydrogen gas circuit includes a one-way charging valve, a high-pressure gas storage cylinder connected to the rear side of the one-way charging valve, and a diaphragm pressure regulating valve connected to the rear side of the high-pressure gas storage cylinder. The rear side of the diaphragm pressure regulating valve forms three paths, the first path is connected to the third pressure sensor, the second path is connected to the first normally closed ultra-micro solenoid valve group, the first normally closed ultra-micro solenoid valve group is connected to the FID, the third path is connected to the second normally closed ultra-micro solenoid valve group, the rear side of the second normally closed ultra-micro solenoid valve group is connected to the third gas resistance, and the rear end of the third gas resistance is connected to the FID; Among them, the adaptive sample gas path operation mode: under the action of the first diaphragm pump, the sample gas passes through the first filter membrane and the first diaphragm pump in turn, and then the gas is divided into four paths, the first path flows into the FID through the first air resistance, the second path flows into the first pressure sensor, and the third path is discharged through the first throttle valve. This sampling system can discharge excess gas through the first throttle valve and obtain a stable flow of sample gas at the first air resistance; as the number of particles in the filter membrane increases, the speed of the first diaphragm pump motor is adjusted through the first pressure sensor to keep the gas in the gas path within the preset stable range; Adaptive air circuit operation mode: Under the action of the second diaphragm pump, the measured gas (containing high-concentration non-methane total hydrocarbons) passes through the second filter and the second diaphragm pump in sequence to obtain air, and then the air is divided into two paths, the first path flows into the FID through the second air resistance, and the second path flows into the second pressure sensor. This sampling system obtains a stable flow of air at the second air resistance; as the number of particles in the metal sintered filter element increases, the speed of the second diaphragm pump motor is adjusted through the second pressure sensor to keep the gas in the air circuit within the preset stable range; Operation mode and principle of hydrogen gas circuit: the gas in the gas source is stored in the high-pressure gas storage cylinder through the one-way charging valve, and the diaphragm pressure regulating valve is adjusted to adjust the outlet pressure to the required pressure value, and the gas is output to the first normally closed ultramicro solenoid valve and the second and normally closed ultramicro solenoid valves. The gas in the first normally closed ultramicro solenoid valve is directly transmitted to the FID, and the gas in the second normally closed ultramicro solenoid valve is transmitted to the FID after steady flow through the third gas resistance. When a large amount of hydrogen is required for FID ignition, the first normally closed ultramicro solenoid valve and the second normally closed ultramicro solenoid valve are opened at the same time; when a small amount of gas is required for stable operation of FID, the first normally closed ultramicro solenoid valve is closed, the second normally closed ultramicro solenoid valve is opened, and the second normally closed ultramicro solenoid valve outputs a stable small flow gas through the third gas resistance.

2. A small-scale high-concentration VOCs gas detection method according to claim 1, characterized in that: The first filter for filtering the sample gas comprises a first filter element, and the first filter element is made of porous polytetrafluoroethylene.

3. A small-scale high-concentration VOCs gas detection method according to claim 2, characterized in that: The porous polytetrafluoroethylene material has a pore size of 0.4-0.5 microns.

4. A small-scale high-concentration VOCs gas detection method according to claim 3, characterized in that: The porous polytetrafluoroethylene material has a pore size of 0.45 microns.

5. A small-scale high-concentration VOCs gas detection method according to claim 1, characterized in that: The second filter for filtering the sample gas comprises a second filter element, and the second filter element is a primary filter cotton or a molecular sieve or an activated carbon or a metal sintered filter element.

6. A small-scale high-concentration VOCs gas detection method according to claim 1, characterized in that: One end of the one-way inflation valve is directly connected to the high-pressure gas storage bottle, and the other end is a high-pressure quick connector connected to the quick connector of the gas source.

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