1. A method for rapidly detecting total volatile organic compounds is characterized by comprising the following steps:

s01, arranging the sample collection tube (9) in the area to be detected;

s02, starting an air compressor (1) to extract air in the area to be detected, and pressing the air into the separation cavity (2) after pressurization;

s03, counting the total amount of the pumped air through the flow sensor (7) when the air passes through the air inlet channel (6);

s04, compressing the air passing through the area to be detected in the separation cavity (2) to increase the pressure in the separation cavity (2), and enabling various volatile organic compounds in the air to enter the detection cavity (4) through the separation membrane (3) under the action of the pressure;

s05, detecting the concentration of different volatile organic compounds by gas sensors (14) aiming at different volatile organic compounds in the detection cavity (4) respectively;

s06, when the gas sensor (14) of one volatile organic compound detects that the concentration of the corresponding volatile organic compound reaches a detection value, calculating the concentration of the corresponding volatile organic compound in the air by recording the amount of the air entering counted by the flow sensor (7) at the moment;

s07, when the gas sensor (14) of the corresponding volatile organic compound component in S06 detects that the concentration of the corresponding volatile organic compound component reaches a detection intermediate value, calculating the concentration of the corresponding volatile organic compound component in the air by recording the amount of the air entering counted by the flow sensor (7) at the moment;

s08, when the gas sensor (14) of the corresponding volatile organic compound component in S06 detects that the concentration of the corresponding volatile organic compound component reaches the detection threshold, the air intake amount counted by the flow sensor (7) at the moment is recorded again to calculate the concentration of the corresponding volatile organic compound component in the air;

s09, continuously operating the air compressor (1) until the pressure of the separation cavity (2) reaches a threshold value;

s10, when the pressure in the separation cavity (2) reaches a threshold value, averaging the concentrations calculated in the three times in the S06, the S07 and the S08 to calculate the concentration value of the corresponding volatile organic compound component in the air;

s11, when the pressure in the separation cavity (2) reaches a threshold value, calculating the concentration value of the corresponding volatile organic compound component in the air by averaging the volatile organic compound components which are not collected for the same three times of concentration values according to the collected concentration values;

s12, when the pressure in the separation cavity (2) reaches a threshold value, calculating the concentration of the corresponding volatile organic compound component in the air according to the current concentration of the volatile organic compound which does not reach the detection threshold value;

s13, when the pressure in the separation cavity (2) reaches a threshold value, the gas sensor (14) does not detect that the concentration value of the volatile organic compounds is zero;

and S14, summarizing the calculated corresponding organic matter concentrations in S10, S11, S12 and S13, and calculating the total volatile organic matter concentration.

2. The method for rapidly detecting total volatile organic compounds according to claim 1, wherein: the detection value in S06 is the lowest concentration value in the optimal detection range of the corresponding gas sensor (14).

3. The method for rapidly detecting total volatile organic compounds according to claim 1, wherein: the detection intermediate value in S07 is the intermediate value of the optimal detection range of the corresponding gas sensor (14).

4. The method for rapidly detecting total volatile organic compounds according to claim 1, wherein: the detection threshold in S08 is the highest concentration value of the optimal detection range of the corresponding gas sensor (14).

5. The utility model provides a device of total volatile organic compounds of short-term test, includes air compressor machine (1), separation chamber (2) and detection chamber (4), its characterized in that: separation chamber (2) and detect between chamber (4) fixed mounting have separation membrane (3), the output and the separation chamber (2) of air compressor machine (1) are linked together, and the input of air compressor machine (1) is provided with inlet channel (6), the one end fixedly connected with sample acquisition pipe (9) of air compressor machine (1) are kept away from in inlet channel (6), and there is flow sensor (7) in the middle section of inlet channel (6), the inner chamber bottom that detects chamber (4) is provided with detects seat (5).

6. The device for rapidly detecting total volatile organic compounds according to claim 5, wherein: and an air filter (8) is arranged at one end, far away from the air compressor (1), of the air inlet channel (6), and the air filter (8) is arranged corresponding to the sample collecting pipe (9).

7. The device for rapidly detecting total volatile organic compounds according to claim 5, wherein: the upside of air compressor machine (1) is provided with control terminal (15), control terminal (15) and air compressor machine (1), detect seat (5) and flow sensor (7) electric connection.

8. The device for rapidly detecting total volatile organic compounds according to claim 5, wherein: the detection device is characterized in that a liquid collecting pipe (10) is fixedly connected to the center of the lower end of the detection cavity (4), the liquid collecting pipe (10) is a transparent glass pipe, a photometer (19) is arranged at the bottom of the liquid collecting pipe (10), a light supplementing lamp (20) is arranged above the photometer (19), the light supplementing lamp (20) is arranged at the bottom of the side wall of the liquid collecting pipe (10) close to the bottom, and an electric heating jacket (18) is arranged on the outer wall of the upper section of the liquid collecting pipe (10).

9. The device for rapidly detecting total volatile organic compounds according to claim 5, wherein: the evaporation end of the heat pipe heat exchanger (11) is buried at the upper end of the inner cavity of the separation membrane (3), the condensation end of the heat pipe heat exchanger (11) is fixedly connected with a heat dissipation plate (12), the inner cavity of the heat dissipation plate (12) is fixedly connected with a semiconductor refrigeration sheet (13), and the refrigeration surface of the semiconductor refrigeration sheet (13) is abutted to the condensation end of the heat pipe heat exchanger (11).

10. The device for rapidly detecting total volatile organic compounds according to claim 5, wherein: the lateral wall of separation chamber (2) is close to upper end department and is provided with blast pipe (21), and blast pipe (21) end fixed mounting has discharge valve (17), blast pipe (21) middle part fixed mounting has electron barometer (16).

Background

Volatile organic pollutants (VOC) are organic compounds with a saturated vapor pressure of more than 70.9Pa or a boiling point of less than 260 ℃ at room temperature, and Total Volatile Organic Compounds (TVOC) are the sum of various volatile organic pollutants, including benzene series, alkanes, alkenes, halogenated hydrocarbons, esters, ketoaldehydes and other volatile organic compounds. The TVOC outdoor pollution source mainly comes from fuel combustion and transportation, and the indoor pollution source mainly comes from building materials such as artificial boards, plastic boards, foam heat insulation materials and the like, and decorative materials such as coatings, paints and adhesives. The volatile organic compounds have irritation, teratogenicity, carcinogenicity and mutagenicity, can directly affect the skin and mucous membranes to cause acute damage to human bodies, can also affect the functions of digestive systems to cause symptoms such as inappetence, nausea and the like, and can even affect the functions of central nervous systems to cause symptoms such as dizziness, somnolence, weakness, chest distress and the like, thereby causing serious threat to the health of the human bodies. Moreover, volatile organic compounds can cause atmospheric pollution, soil pollution, water pollution and the like, and destroy the ecological environment. Therefore, the method has important significance for enhancing the detection of the total volatile organic compounds.

The standard method for detecting TVOC in indoor air is specified by the civil building engineering indoor environmental pollution control Specification (GB 50325-2020): the TVOC in air is enriched by a Tenax-TA tube, TVOC desorption gas is obtained after thermal desorption, and the TVOC desorption gas is injected into a gas chromatograph for chromatographic analysis. All compounds identified from the chromatogram between n-hexane and n-hexadecane were quantified and the concentration of unidentified volatile organic compounds was calculated using the response coefficient of toluene. The method has the disadvantages of low detection limit, good precision and accuracy, long time consumption, 1h consumption for analyzing one sample, and difficult realization of real-time online monitoring. In recent years, some TVOC detection methods such as gas chromatography-mass spectrometry, high performance liquid chromatography, ion chromatography, fluorescence spectroscopy, reflection interference spectroscopy and the like have emerged, and although these large-scale precise instruments can perform comprehensive and accurate analysis on compounds, the instruments are expensive, the operation is complex and time-consuming, and real-time online analysis is not easy to realize, so that the application of the TVOC detection methods is limited. The gas sensor has the characteristics of simple structure, small volume, relatively low manufacturing cost, convenient operation, real-time online monitoring and the like, and the application of the gas sensor in the detection of TVOC is emphasized.

The linear range of a gas sensor refers to the range where the output is proportional to the input. Theoretically, the sensitivity remains constant in this range. The wider the linear range of the sensor, the larger the measuring range of the sensor, and certain measuring accuracy can be ensured. In practice, however, any sensor cannot guarantee absolute linearity, which is also relative. When the required measurement accuracy is relatively low, the sensor with a small nonlinear error can be approximately regarded as linear in a certain range, which brings great convenience to measurement, but because the TVOC contains a plurality of types of gases, the linear ranges of the gas sensors corresponding to different types of volatile organic compounds are in different concentration intervals, and the contents of the volatile organic compounds in different air are different, in the same environment, the concentration of the volatile organic compounds in the air can not be uniformly detected through the gas sensors, so that the TVOC detection result has a large deviation from the actual content.

Disclosure of Invention

The invention aims to provide a method for rapidly detecting total volatile organic compounds, which can realize membrane separation and concentration of TVOC and improve the TVOC concentration of a detection area, so that each volatile organic compound gas sensor is positioned in a linear range during detection, the detection efficiency is improved, and the detection precision is ensured.

The second objective of the present invention is to provide a device for rapidly detecting total volatile organic compounds.

In order to solve the problems, the invention adopts the following technical scheme:

a method for rapidly detecting total volatile organic compounds comprises the following steps:

s01, arranging the sample collection tube in the area to be detected;

s02, starting an air compressor to extract air in the area to be detected, pressurizing the air and pressing the air into the separation cavity;

s03, counting the total amount of the pumped air through a flow sensor when the air passes through the air inlet channel;

s04, compressing the air passing through the area to be detected in the separation cavity to increase the pressure in the separation cavity, and allowing the volatile organic compounds in the air to enter the detection cavity through the separation membrane under the action of the pressure;

s05, detecting the concentration of different volatile organic compounds respectively by gas sensors aiming at different volatile organic compounds in the detection cavity;

s06, when the gas sensor of one volatile organic compound detects that the concentration of the corresponding volatile organic compound reaches the detection value, calculating the concentration of the corresponding volatile organic compound in the air by recording the amount of the air entering counted by the flow sensor at the moment;

s07, when the gas sensor of the corresponding volatile organic compound component in S06 detects that the concentration of the corresponding volatile organic compound component reaches a detection intermediate value, calculating the concentration of the corresponding volatile organic compound component in the air by recording the amount of the air entering counted by the flow sensor at the moment;

s08, when the gas sensor of the corresponding volatile organic compound component in S06 detects that the concentration of the corresponding volatile organic compound component reaches the detection threshold, the air intake amount counted by the flow sensor at the moment is recorded again to calculate the concentration of the corresponding volatile organic compound component in the air;

s09, continuously working by the air compressor until the pressure of the separation cavity reaches a threshold value;

s10, when the pressure in the separation cavity reaches a threshold value, averaging the concentrations calculated in the three steps of S06, S07 and S08 to calculate the concentration value of the corresponding volatile organic compound component in the air;

s11, when the pressure in the separation cavity reaches a threshold value, calculating the concentration value of the corresponding volatile organic compound component in the air by averaging the volatile organic compound components which are not collected for three times according to the collected concentration values;

s12, when the pressure in the separation cavity reaches a threshold value, calculating the concentration of the corresponding volatile organic compound component in the air according to the current concentration of the volatile organic compound which does not reach the detection threshold value;

s13, when the pressure in the separation cavity reaches a threshold value, the concentration of the volatile organic compounds of which the concentration value is not detected by the gas sensor is zero;

and S14, summarizing the calculated corresponding organic matter concentrations in S10, S11, S12 and S13, and calculating the total volatile organic matter concentration.

As a preferable scheme of the present invention, the air inlet of the sample collection tube in S01 is suspended, and the air inlet is vertically disposed on the respiratory belt.

In a preferred embodiment of the present invention, the detection value in S06 is the lowest concentration value in the optimal detection range of the corresponding gas sensor.

In a preferred embodiment of the present invention, the detection middle value in S07 is a middle value of an optimal detection range of the corresponding gas sensor.

In a preferred embodiment of the present invention, the detection threshold in S08 is the highest concentration value in the optimal detection range of the corresponding gas sensor.

In a preferred embodiment of the present invention, in S09, the total amount of air when the pressure in the separation chamber reaches the threshold value and the concentration of the volatile organic compounds calculated from the detection values of the volatile organic compounds in the detection chamber are both lower than a predetermined minimum value.

The utility model provides a device for short-term test total volatile organic compound, includes air compressor machine, disengagement chamber and detects the chamber, fixed mounting has the separation membrane between disengagement chamber and the detection chamber, the output and the disengagement chamber of air compressor machine are linked together, and the input of air compressor machine is provided with inlet channel, inlet channel keeps away from the one end fixedly connected with sample collection pipe of air compressor machine, and inlet channel's middle section has flow sensor, the inner chamber bottom that detects the chamber is provided with detects the seat.

As a preferable scheme of the invention, an air filter is arranged at one end of the air inlet channel, which is far away from the air compressor, and the air filter is arranged corresponding to the sample collecting pipe.

As a preferred scheme of the present invention, a control terminal is disposed on an upper side of the air compressor, and the control terminal is electrically connected to the air compressor, the detection seat and the flow sensor.

According to a preferable scheme of the invention, the center of the lower end of the detection cavity is fixedly connected with a liquid collecting tube, the liquid collecting tube is a transparent glass tube, the bottom of the liquid collecting tube is provided with a photometer, a light supplementing lamp is arranged above the photometer and is arranged close to the bottom of the side wall of the liquid collecting tube, and the outer wall of the upper section of the liquid collecting tube is provided with an electrothermal jacket.

According to a preferable scheme of the invention, the upper end of the inner cavity of the separation membrane is embedded with the evaporation end of the heat pipe heat exchanger, the condensation end of the heat pipe heat exchanger is fixedly connected with the heat dissipation plate, the inner cavity of the heat dissipation plate is fixedly connected with the semiconductor refrigeration piece, and the refrigeration surface of the semiconductor refrigeration piece is abutted against the condensation end of the heat pipe heat exchanger.

As a preferable scheme of the invention, an exhaust pipe is arranged on the side wall of the separation cavity close to the upper end, an exhaust valve is fixedly mounted at the tail end of the exhaust pipe, and an electronic barometer is fixedly mounted in the middle of the exhaust pipe.

Compared with the prior art, the invention has the advantages that:

the scheme compresses air in the separation cavity through the air compressor, separates TVOC through the separation membrane, concentrates and enriches TVOC in the detection cavity, enables all volatile organic compound gas sensors to be located in a linear range during detection, enables detection results of various volatile organic compound concentrations to be more accurate through numerical values of detection positions of the gas sensors in the linear range, calculates the concentrations of various volatile organic compounds in the air according to the total air inflow at the moment, obtains the total volatile organic compound content through summary statistics of various volatile organic compound concentrations, directly detects the volatile organic compound concentrations through the gas sensors, is quicker than detection methods such as gas chromatography-mass spectrometry, high performance liquid chromatography, ion chromatography, fluorescence spectroscopy, reflection interference spectroscopy and the like, has higher detection efficiency than an integrated detection device, and has higher detection efficiency due to continuous pressurization of the air compressor and membrane separation of the separation membrane, make various volatile organic compounds concentration that detect the intracavity constantly improve, detect organic matter concentration when volatile organic compounds concentration is in linear range through gas sensor for gas sensor is more accurate to the result that various volatile organic compounds concentration detected, has improved the detection precision of device.

Drawings

Fig. 1 is a schematic view of the internal structure of the present invention.

FIG. 2 is a flow chart of the detection method of the present invention.

The reference numbers in the figures illustrate:

1. an air compressor; 2. a separation chamber; 3. a separation membrane; 4. a detection chamber; 5. a detection seat; 6. an air intake passage; 7. a flow sensor; 8. an air cleaner; 9. a sample collection tube; 10. a liquid collecting pipe; 11. a heat pipe heat exchanger; 12. a heat dissipation plate; 13. a semiconductor refrigeration sheet; 14. a gas sensor; 15. a control terminal; 16. an electronic barometer; 17. an exhaust valve; 18. an electric heating jacket; 19. a photometer; 20. a light supplement lamp; 21. and (4) exhausting the gas.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by those skilled in the art without any inventive work are within the scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top/bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "sleeved/connected," "connected," and the like are to be construed broadly, e.g., "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example (b):

referring to fig. 1-2, a device for rapidly detecting total volatile organic compounds, comprising an air compressor 1, a separation chamber 2 and a detection chamber 4, wherein a separation membrane 3 is fixedly installed between the separation chamber 2 and the detection chamber 4, an output end of the air compressor 1 is communicated with the separation chamber 2, an input end of the air compressor 1 is provided with an air inlet passage 6, one end of the air inlet passage 6, which is far away from the air compressor 1, is fixedly connected with a sample collecting pipe 9, a flow sensor 7 is arranged in the middle section of the air inlet passage 6, a detection seat 5 is arranged at the bottom of an inner cavity of the detection chamber 4, a plurality of gas sensors are embedded in the detection seat 5, and each gas sensor corresponds to different types of volatile organic compounds.

Specifically, one end of the air inlet channel 6, which is far away from the air compressor 1, is provided with an air filter 8, and the air filter 8 is arranged corresponding to the sample collecting pipe 9.

In this embodiment, air cleaner 8 is polyurethane filter core air cleaner, and air cleaner 8 intussuseption is filled with the cotton that absorbs water, filters dust and steam in the air that will get into inlet channel 6 through air cleaner 8, avoids dust and steam pollution separation membrane 3.

Specifically, the upside of air compressor machine 1 is provided with control terminal 15, and control terminal 15 and air compressor machine 1, detect seat 5 and flow sensor 7 electric connection.

In this embodiment, the control terminal 15 is an STM32 ARM control board, and can receive and process the data transmitted by the detection seat 5 and the flow sensor 7, and perform calculation processing.

Specifically, the lower extreme center fixedly connected with collector tube 10 that detects chamber 4, and collector tube 10 is the transparent glass pipe, and the bottom of collector tube 10 is provided with photometer 19, and photometer 19 top is provided with light filling lamp 20, and light filling lamp 20 is close to the lateral wall bottom setting of collector tube 10, and the upper segment outer wall of collector tube 10 is provided with electrothermal jacket 18.

In this embodiment, wherein photometer 19 is LXD/GB5-A1DPZ type photosensitive sensor, can observe through photometer 19 collector tube 10 and detect whether the volatile organic compounds in chamber 4 condenses, can rethread electrothermal jacket 18 after condensing heats collector tube 10 and make the condensate evaporate, has guaranteed the accuracy of detection seat 5 testing result.

Specifically, the evaporation end of the heat pipe heat exchanger 11 is buried in the upper end of the inner cavity of the separation membrane 3, the condensation end of the heat pipe heat exchanger 11 is fixedly connected with a heat dissipation plate 12, the inner cavity of the heat dissipation plate 12 is fixedly connected with a semiconductor refrigeration piece 13, and the refrigeration surface of the semiconductor refrigeration piece 13 is abutted to the condensation end of the heat pipe heat exchanger 11.

In this embodiment, detect and accomplish back semiconductor refrigeration piece 13 refrigeration, then extract the heat of air in the separation chamber 2 through heat pipe exchanger 11, thereby reduce the temperature that detects the interior air of chamber 4 through the transmission of air, make the volatile organic compounds that detect in the chamber 4 can condense, in the volatile organic compounds entering collecting tube 10 after the condensation, it is healthy to avoid the volatile organic compounds of high concentration to influence the measurement personnel, the volatile organic compounds follow-up processing of being convenient for simultaneously and retest.

Specifically, an exhaust pipe 21 is arranged on the side wall of the separation cavity 2 near the upper end, an exhaust valve 17 is fixedly mounted at the tail end of the exhaust pipe 21, and an electronic barometer 16 is fixedly mounted in the middle of the exhaust pipe 21.

In this embodiment, the electronic barometer 16 is a CBJ-SKT-1-electronic barometer, the electronic barometer 16 is electrically connected to the control terminal 15, the electronic barometer 16 monitors whether the air pressure in the separation chamber 2 reaches a threshold value, and the control terminal 15 controls the device to stop operating when the air pressure in the separation chamber 2 reaches the threshold value.

When the device is used, air at a detection position passes through the sample collecting pipe 9 and the air filter 8 under the traction of the air compressor 1, the air passes through the air inlet channel 6 after being filtered and purified by the air filter 8 and is pumped into the separation cavity 2, the flow sensor 7 at the middle section of the air inlet channel 6 counts the total amount of the air pumped into the separation cavity 2, the air in the separation cavity 2 is continuously pressurized and compressed, pressure difference is formed between two sides of the separation membrane 3, volatile organic matters in the air in the separation cavity 2 enter the detection cavity 4 through the separation membrane 3 under the action of the pressure difference and are continuously enriched in the detection cavity 4, the concentration of the volatile organic matters in the detection cavity 4 is continuously increased, the gas sensors 14 in the detection seat 5 respectively detect the concentrations of different types of the volatile organic matters, and when the concentration detected by the gas sensors 14 reaches the optimal detection range, the concentration monitored by the flow sensor 7 and pumped into the separation cavity 2 is respectively monitored according to the end value and the middle value of the optimal detection range The total amount of gas calculates the concentration of volatile organic compounds in the air, and the concentration values calculated three times are averaged to calculate the corresponding concentration of volatile organic compounds, and finally the concentrations of corresponding different types of volatile organic compounds counted by the plurality of gas sensors 14 are summed to obtain the concentration of total volatile organic compounds.

A method for rapidly detecting total volatile organic compounds comprises the following steps:

s01, arranging the sample collection tube 9 in the area to be detected;

wherein the air inlet of sample collection pipe 9 is unsettled to be set up, and the air inlet sets up perpendicularly in the respiratory belt for sample collection pipe 9's air inlet keeps the distance with common VOC volatilization sources such as wall body and ground, has avoided near volatile organic compounds of VOC volatilization source high concentration to the influence of testing result, has guaranteed the accuracy of testing result.

S02, starting the air compressor 1 to extract air in the area to be detected, pressurizing the air and pressing the air into the separation cavity 2;

s03, counting the total amount of the pumped air through the flow sensor 7 when the air passes through the air inlet channel 6;

the flow sensor 7 adopts a CW-JSG type metal pipe float flowmeter, has the characteristics of small pressure loss, convenient use and the like, can be used for medium flow measurement of low flow rate and small flow, has high measurement precision, is convenient and practical, has a remote transmission function, and can convert detected flow data into electric signals to be transmitted to a control terminal.

S04, compressing the air passing through the area to be detected in the separation cavity 2 to increase the pressure in the separation cavity 2, and making various volatile organic compounds in the air enter the detection cavity 4 through the separation membrane 3 under the action of the pressure;

above-mentioned separation membrane 3 is made through plasma grafting polysiloxane active layer on the polypropylene hollow fiber basement membrane, can effectively separate volatile organic compounds such as formaldehyde in the air, toluene and xylene, the atmospheric pressure that detects in the chamber 4 is standard atmospheric pressure, the air is constantly being pumped into in the separation chamber 2, the pressure in the separation chamber 2 continuously improves, because the pressure in the separation chamber 3 is greater than and detects chamber 4, volatile organic compounds in the separation chamber 2 passes through separation membrane 3 and gets into in detecting chamber 4, enrichment in detecting chamber 4.

S05, detecting the concentration of different volatile organic compounds respectively by the gas sensor 14 aiming at different volatile organic compounds in the detection cavity 4;

the gas sensor 14 described above employs JXM-C₆H₆、HD-T700-CH₂The O and PID photo-ion gas sensors work in combination, and can detect the concentration of common volatile organic compounds in the air, convert the concentration into electric signal data, convert the electric signal data into an electric signal and transmit the electric signal data to the control terminal 15.

S06, when the gas sensor 14 of one volatile organic compound detects that the concentration of the corresponding volatile organic compound reaches the detection value, calculating the concentration of the corresponding volatile organic compound in the air by recording the amount of the air entering counted by the flow sensor 7 at the moment;

the detection value is the lowest concentration value in the optimal detection range of the corresponding gas sensor 14;

s07, when the gas sensor 14 of the corresponding volatile organic compound component in S06 detects that the concentration of the corresponding volatile organic compound component reaches a detection intermediate value, calculating the concentration of the corresponding volatile organic compound component in the air by recording the amount of the entering air counted by the flow sensor 7 at the moment;

the detection intermediate value is an intermediate value of the optimum detection range of the corresponding gas sensor 14.

S08, when the gas sensor 14 of the corresponding volatile organic compound component in S06 detects that the corresponding volatile organic compound component concentration reaches the detection threshold, the air intake amount counted by the flow sensor 7 at that time is recorded again to calculate the concentration of the corresponding volatile organic compound component in the air;

the detection threshold value is the highest concentration value in the optimal detection range of the corresponding gas sensor 14.

Volume V in the detection chamber 4₀I.e. the volume of air remaining in the detection chamber 4 at atmospheric pressure is V₀When the volatile organic compound concentration detected by the gas sensor 14 is X, it is found that:

m＝X*V₀；

wherein m is the mass of the volatile organic compounds detected by the corresponding gas sensor 14 in the detection cavity 4;

the total volume of air pumped into the separation chamber 2 at this time, as measured by the flow sensor 7, is V₁From this, the concentration Y of the corresponding volatile organic compounds in the air pumped into the separation chamber 2 can be calculated according to the concentration calculation formula:

Y＝m/V₁；

s09, the air compressor 1 continuously works until the pressure of the separation cavity 2 reaches a threshold value;

s10, when the pressure in the separation cavity 2 reaches a threshold value, averaging the concentrations calculated in the three times in S06, S07 and S08 to calculate the concentration value of the corresponding volatile organic compound component in the air;

the concentration value of the volatile organic compounds detected for each gas sensor 14 is calculated as Y in S06, S07 and S08, respectively₁、Y₂And Y₃And averaging to obtain the concentration value Y of the detected volatile organic compounds₀：

Y₀＝(Y₁+Y₂+Y₃)/3；

The concentration of the volatile organic compounds is calculated by averaging the concentration of the volatile organic compounds calculated by the end value and the middle value of the optimal detection range, so that the influence of detection errors on detection results can be reduced, and the accuracy of the detection results is improved.

S11, when the pressure in the separation cavity 2 reaches a threshold value, calculating the concentration value of the corresponding volatile organic compound component in the air by averaging the volatile organic compound components which are not collected for three times according to the collected concentration values;

s12, when the pressure in the separation cavity 2 reaches a threshold value, calculating the concentration of the corresponding volatile organic compound component in the air according to the current concentration of the volatile organic compound which does not reach the detection threshold value;

s13, when the pressure in the separation chamber 2 reaches the threshold value, the gas sensor 14 does not detect that the concentration of the volatile organic compounds is zero;

and S14, summarizing the calculated corresponding organic matter concentrations in S10, S11, S12 and S13, and calculating the total volatile organic matter concentration.

The total volatile organic concentration is equal to the sum of the concentrations of all volatile organic compounds, and the total volatile organic concentration is obtained by summing the concentrations of the plurality of volatile organic compounds calculated in step S10.

The air is compressed in the separation cavity 2 by the air compressor 1, and then the TVOC is separated by the separation membrane 3, so that the TVOC is concentrated and enriched in the detection cavity 4, thereby the concentration values obtained by calculating various volatile organic compounds are all in a linear range, further the concentration of the total volatile organic compounds in the air is calculated by the concentration of each volatile organic compound, the concentration of the volatile organic compounds is directly detected by the gas sensor 14, and the detection device is quicker than detection methods such as gas chromatography-mass spectrometry, high performance liquid chromatography, ion chromatography, fluorescence spectroscopy, reflection interference spectroscopy and the like, and has higher detection efficiency than an integrated detection device, because of the continuous pressurization of the air compressor 1 and the membrane separation of the separation membrane 3, the concentration of each volatile organic compound in the detection cavity 4 is continuously improved, and the concentration of the organic compound is detected by the gas sensor 14 when the concentration of the volatile organic compound is in the linear range, the gas sensor 14 can detect the concentration of various volatile organic compounds more accurately, and the detection precision of the device is improved.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the equivalent replacement or change according to the technical solution and the modified concept of the present invention should be covered by the scope of the present invention.