Calibration device and method for micro trace gas analyzer

Abstract

The invention belongs to the field of instrument calibration, and relates to a calibration device and method for a micro trace gas analyzer. In the calibration device, an electronic pressure controller is installed in an inert gas protection container, a flow control piece and a constant-temperature cavity are installed in a constant-temperature box, a permeation tube is installed in the constant-temperature cavity and connected with an automatic weighing module, and the flow control piece and the constant-temperature cavity are connected with a gas mixer. And the gas mixer is respectively connected with the intelligent diagnosis module and the micro trace gas analyzer to be calibrated through the flow regulator. In the calibration method, the upper computer calculates the component concentration of the standard substance in the calibration gas, sends a control command according to the calculation result, and automatically adjusts the pressure value of the electronic pressure controller, the temperature value of the constant temperature box and the flow value of the flow regulator until the component concentration of the standard substance in the calibration gas meets the calibration requirement. Under the condition of low gas flow, the accuracy is higher, the reliability is better, automatic operation is achieved, manual operation is not needed, the calibration efficiency is high, and the calibration result is accurate.

Description

Technical Field

[0001] The invention belongs to the technical field of instrument calibration, and in particular relates to a calibration device and method for a trace gas analyzer. Background Art

[0002] Micro-trace gas analyzer is a high-precision instrument, which is specially used to detect and analyze the components of extremely low concentration gases in air or high-purity gases. Its main features are high sensitivity and high precision. It can detect 10 -6 Trace gas changes below the mol / mol level are widely used in a variety of scenarios that require precise gas monitoring. In the semiconductor industry, it is mainly used to monitor and control the purity and composition of gases in the manufacturing process to ensure product quality and process stability; in the medical and pharmaceutical industries, it is mainly used to analyze patients' exhaled gases to help with disease diagnosis and health monitoring. In addition, it is also used to monitor the gas composition generated during the reaction process in pharmaceutical and biotechnology research; in the defense and military industry, it is mainly used for leak monitoring of various weapon equipment warehouses and fuel storage tanks; in the aerospace field, it is mainly used for life maintenance system monitoring of manned spaceflight and spacecraft leak monitoring.

[0003] Since the trace gas analyzer is used to detect extremely low concentrations of gas components, any slight error may lead to inaccurate results. Regular calibration can ensure that the instrument's measurement data is accurate and reliable, and avoid misjudgments and decisions caused by measurement deviations. In addition, during use, the analyzer's sensors and detection systems may be affected by environmental factors (such as temperature, humidity, pollutants, etc.), resulting in performance degradation. Calibration can detect and adjust these deviations to maintain the optimal performance of the instrument. In addition, many industries (such as environmental monitoring, medical care, food safety, etc.) have strict requirements on the accuracy of gas detection. Regular calibration ensures that the analyzer complies with relevant standards and regulations to avoid legal and economic consequences caused by inaccurate data. Finally, through regular calibration and maintenance, potential problems of the instrument can be discovered and repaired in a timely manner, the frequency of failures can be reduced, the service life of the equipment can be extended, and maintenance and replacement costs can be reduced.

[0004] However, due to the lack of 1×10 -6For standard substances with concentrations below mol / mol, the calibration method of such instruments generally uses high-concentration standard substances for calibration, or uses a dynamic dilution device to dilute high-concentration standard substances to low concentrations. The above methods have some shortcomings: (1) There are problems of insufficient precision and poor stability in controlling the concentration and flow rate of standard substances. Especially when preparing high-precision and low-concentration standard substances, the lack of standard substance flow control and mixing accuracy will directly affect the accuracy of the gas distribution results; (2) The efficiency of standard substance use may be poor, resulting in a large amount of standard substance waste. Especially when using high-cost standard substances, the increase in standard substance consumption will significantly increase the operating cost; (3) The degree of automation is low, and the standard substance source needs to be replaced and installed repeatedly. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a high-precision, automated, and efficient trace gas detector calibration device and method. The technical solution adopted by the present invention is as follows:

[0006] A calibration device for a trace gas analyzer comprises a sealed standard substance gas cylinder, an inert gas source container, an inert gas protection container, a thermostatic box and a waste gas recovery container, wherein the inert gas protection container is provided with an electronic pressure controller 1, an electronic pressure controller 2, an electronic pressure controller 3 and an electronic pressure controller 4, the thermostatic box is provided with a flow control component 1, a flow control component 2, a flow control component 3, a constant temperature chamber, an automatic weighing module and a gas mixer, the constant temperature chamber is provided with a plurality of permeation tubes, the permeation tubes are connected to the automatic weighing module; the standard substance gas cylinder is connected to the gas mixer via the electronic pressure controller 2 and the flow control component 1, the inert gas source container ... An inert gas recovery module, an inert gas protection container, an electronic pressure controller three and an electronic pressure controller four, wherein the inert gas recovery module is connected to the inert gas protection container, the electronic pressure controller three is sequentially connected to the flow control component two, the constant temperature chamber and the gas mixer, a valve is arranged between the constant temperature chamber and the gas mixer, the electronic pressure controller four is sequentially connected to the flow control component three and the gas mixer, the gas mixer is sequentially connected to the electronic pressure controller one and the waste gas recovery container, the gas mixer is respectively connected to the intelligent diagnosis module and the trace gas analyzer to be calibrated, the intelligent diagnosis module is connected to the waste gas recovery container, and the automatic weighing module and the intelligent diagnosis module are respectively electrically connected to the host computer.

[0007] Preferably, the flow control element 1, the flow control element 2 and the flow control element 3 all include a VCR connector and a sharp hole, the sharp hole is embedded in the inner cavity of the VCR connector, and the diameter in the middle of the sharp hole is smaller than the diameter at both ends.

[0008] Preferably, a first flow regulator is arranged between the gas mixer and the intelligent diagnosis module, and a second flow regulator is arranged between the gas mixer and the trace gas analyzer to be calibrated.

[0009] Preferably, the inert gas source container is connected to a primary purifier, the primary purifier is respectively connected to a pair of secondary purifiers, and the pair of secondary purifiers are respectively connected to an electronic pressure controller three and an electronic pressure controller four via a three-way pipe joint.

[0010] Preferably, the intelligent diagnosis module is an online continuous gas monitoring device based on the principle of cavity enhanced absorption spectroscopy.

[0011] Preferably, the inert gas recovery module comprises an inert gas recovery container, a diaphragm compressor, a filling row and a plurality of gas cylinders.

[0012] A calibration method for a trace gas analyzer, using the aforementioned calibration device for a trace gas analyzer, comprises the following steps:

[0013] The host computer controls the thermostat to adjust to the working temperature required for calibration; the standard substance and the purified inert gas are mixed into the calibration gas in the gas mixer, and the calibration gas enters the trace gas analyzer to be calibrated through flow regulator one on one path, and enters the intelligent diagnosis module through flow regulator two on the other path. The diagnostic data obtained by the intelligent diagnosis module is transmitted to the host computer, and the calibration gas output from the intelligent diagnosis module enters the waste gas recovery container as waste gas; the host computer automatically calculates the component concentration of the standard substance in the calibration gas according to the received data and pre-stored parameters, sends a control command according to the calculation result, and automatically adjusts the pressure value of the electronic pressure controller, adjusts the temperature value of the thermostat, and adjusts the flow values ​​of flow regulator one and flow regulator two, until the component concentration of the standard substance in the calibration gas meets the calibration requirements.

[0014] Preferably, if the standard material only includes gaseous standard material a, the standard material a is loaded into a standard material gas cylinder, and the valve between the constant temperature chamber and the gas mixer is closed; if the standard material only includes solid-liquid standard material b, the standard material gas cylinder is not installed, the standard material b is loaded into the permeation tube, the standard material b evaporates into gas and enters the constant temperature chamber from the permeation tube, the standard material b is mixed with the inert gas in the constant temperature chamber and enters the gas mixer, the automatic weighing module automatically weighs the mass of the standard material b evaporated from the permeation tube at a certain interval, and transmits it to the host computer; if the standard material includes both gaseous standard material a and solid-liquid standard material b, the standard material a is loaded into the standard material gas cylinder, the standard material b is loaded into the permeation tube, and the valve between the constant temperature chamber and the gas mixer is opened.

[0015] Preferably, the type, concentration and flow rate of the calibration gas to be prepared, the information of the permeation tube, and the information of the standard substance in the standard substance cylinder and the permeation tube are input into the host computer program module in advance.

[0016] Preferably, the temperature of the thermostat is controlled at 35°C.

[0017] Beneficial effects of the present invention:

[0018] (1) The gas flow control in the prior art usually adopts a gas mass flow controller (MFC), which can accurately measure the gas flow at the "liter / minute" level. However, in the micro-trace gas test, the gas flow is usually at the "ml / minute" level. The traditional method is not accurate enough when adjusting the valve opening under this condition, and the error is large. Therefore, the present invention adopts a different flow control structure (electronic pressure controller-orifice-flow regulator). Compared with the traditional gas mass flow controller method, the present invention obtains different gas mass flow rates by adjusting the different pressures upstream and downstream of the orifice, and uses pressure difference to control the flow. There is no need to adjust the valve opening (the orifice is a throttling mechanical part with a fixed opening). Therefore, the present invention has higher accuracy and better reliability under low gas flow.

[0019] (2) A circulating inert gas positive pressure protection zone is formed by the inert gas source container, the inert gas protection container and the inert gas recovery module, so that the leak-prone components (electronic pressure controller) are protected by the inert gas positive pressure to prevent the reduction of precision and accuracy caused by gas leakage.

[0020] (3) A constant temperature zone is created by the constant temperature box, which can keep the components that are greatly affected by temperature changes (sharp hole, automatic weighing module, constant temperature chamber, permeation tube and gas mixer) in a constant temperature state, thereby improving the precision and accuracy of the output calibration gas.

[0021] (4) In the calibration method, the electronic pressure controller, automatic weighing module, constant temperature chamber, flow regulator and intelligent diagnosis module are all controlled by the host computer. After the inert gas source container, standard material cylinder and permeation tube are installed, the host computer automatically runs through the edited program without other manual operations. The calibration efficiency is high and the calibration results are accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 is a schematic diagram of the overall structure of a calibration device according to Embodiment 1 of the present invention;

[0024] Figure 2is a front view of a flow control component according to a first embodiment of the present invention;

[0025] Figure 3 yes Figure 2 AA section view;

[0026] Figure 4 is a cross-sectional perspective view of an orifice according to a first embodiment of the present invention;

[0027] Figure 5 is a flow chart of the steps of the calibration method of the second embodiment of the present invention;

[0028] Figure 6 Schematic diagram of the measurement principle of the conversion coefficient k in the second embodiment of the present invention;

[0029] In the figure, 1-primary purifier, 2-secondary purifier, 3-standard material cylinder, 4-electronic pressure controller one, 5-electronic pressure controller two, 6-electronic pressure controller three, 7-electronic pressure controller four, 8-flow control component one, 9-flow control component two, 10-flow control component three, 11-automatic weighing module, 12-constant temperature chamber, 13-permeation tube, 14-gas mixer, 15-flow regulator one, 16-flow regulator two, 17-VCR connector, 18-sharp hole, 19-inert gas source container, 20-inert gas recovery module, 21-inert gas protection container, 22-waste gas recovery container, 23-intelligent diagnosis module, 24-constant temperature box, 25-trace gas analyzer to be calibrated. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0031] Embodiment 1

[0032] like Figure 1As shown, a calibration device for a trace gas analyzer includes a sealed standard material cylinder 3, an inert gas source container 19, an inert gas protection container 21, an exhaust gas recovery container 22 and a thermostatic box 24. The standard material cylinder 3 contains a gaseous standard material a, and the inert gas source container 19 contains a high-purity inert gas, generally nitrogen with a purity greater than 99.999%. The inert gas protection container 21 is respectively provided with an electronic pressure controller 1 4, an electronic pressure controller 2 5, an electronic pressure controller 3 6 and an electronic pressure controller 4 7, and the thermostatic box 24 is respectively provided with a flow control component 1 8, a flow control component 2 9, a flow control component 3 10 and a thermostatic chamber 12. The outlet of the inert gas protection container 21 is connected to the inlet of the inert gas recovery module 20 through a sealed pipeline, and the outlet of the inert gas recovery module 20 is connected to the inlet of the inert gas source container 19 through a sealed pipeline. The outlet of the inert gas source container 19 is connected to the inlet of the inert gas protection container 21 and the inlet of the first-stage purifier 1 via a three-way pipe joint and a sealed pipeline, and the outlet of the first-stage purifier 1 is connected to the inlet of a pair of second-stage purifiers 2 via a three-way pipe joint and a sealed pipeline. The high-purity inert gas source is purified in two stages by the first-stage purifier 1 and the second-stage purifier 2, which can greatly reduce the reduction in calibration precision and accuracy caused by insufficient purity of the inert gas source.

[0033] The outlets of the pair of secondary purifiers 2 are connected to the inlet of the electronic pressure controller three 6 and the inlet of the electronic pressure controller four 7 through a three-way pipe joint and a sealed pipeline, respectively. The outlet of the electronic pressure controller three 6 is connected to the inlet of the flow control component two 9 through a sealed pipeline, and the outlet of the electronic pressure controller four 7 is connected to the inlet of the flow control component three 10 through a sealed pipeline. The outlet of the flow control component two 9 is connected to the inlet of the constant temperature chamber 12 through a sealed pipeline. The constant temperature chamber 12 is built with a plurality of permeation tubes 13, and the permeation tubes 13 are filled with volatile solid and liquid standard substances b. The permeation tubes 13 are connected to the automatic weighing module 11, and the standard substance b volatilizes into gas at a given temperature of the constant temperature chamber 12. The outlet of the flow control component three 10 and the outlet of the constant temperature chamber 12 are connected to the inlet of the gas mixer 14 through a sealed pipeline. The outlet of the standard material gas cylinder 3 is connected to the inlet of the electronic pressure controller 25 through a sealed pipeline, and the outlet of the electronic pressure controller 25 is connected to the inlet of the flow control unit 18 through a sealed pipeline, and the outlet of the flow control unit 8 is connected to the inlet of the gas mixer 14 through a sealed pipeline. One outlet of the gas mixer 14 is connected to the inlet of the electronic pressure controller 4 through a sealed pipeline, and the outlet of the electronic pressure controller 4 is connected to the inlet of the waste gas recovery container 22 through a sealed pipeline; the other outlet of the gas mixer 14 is connected to the inlet of the flow regulator 15 and the inlet of the flow regulator 2 16 through a three-way pipe joint and a sealed pipeline, respectively, the outlet of the flow regulator 15 is connected to the micro-trace gas analyzer 25 to be calibrated through a sealed pipeline, the outlet of the flow regulator 2 16 is connected to the inlet of the intelligent diagnosis module 23 through a sealed pipeline, and the outlet of the intelligent diagnosis module 23 is connected to the inlet of the waste gas recovery container 22 through a sealed pipeline. The automatic weighing module 11 and the intelligent diagnosis module 23 are electrically connected to the host computer. A valve is provided between the constant temperature chamber 12 and the gas mixer 14. If only standard substance a is used as the calibration gas, the valve is closed. If standard substance a and standard substance b are mixed into the calibration gas, the valve is opened.

[0034] like Figure 2 , 3 As shown in FIG. 4 , the flow control member 1 8, the flow control member 2 9 and the flow control member 3 10 have the same structure, and all include a VCR connector 17 and a sharp hole 18. The VCR connector 17 and the sharp hole 18 are both existing products, and the sharp hole 18 is embedded in the inner cavity of the VCR connector 17 from one end of the VCR connector 17, and the diameter of the middle of the sharp hole 18 is smaller than the diameters at both ends.

[0035] The intelligent diagnosis module 23 is a gas online continuous monitoring device based on the principle of cavity enhanced absorption spectroscopy, which is used to monitor the concentration of the calibration gas and the degree of change in a continuous time period. When a large fluctuation in the concentration of the calibration gas is detected, an alarm signal is sent to the host computer, and the host computer determines the cause according to the fluctuation (such as insufficient gas source pressure, environmental changes, exhaustion of consumables, module failure, etc.). The intelligent diagnosis module 23 is controlled by the program module in the host computer, and the intelligent diagnosis module 23 sends the monitored concentration value of the calibration gas to the host computer.

[0036] Among them, the inert gas recovery module 20 adopts existing equipment, including an inert gas recovery container, a diaphragm compressor, a filling row and several gas cylinders. The inert gas recovery module 20 is used to recycle the inert gas for protection, fill it into the gas cylinder and recycle it into the inert gas source container 19 for reuse. The inert gas recovery container adopts a sealed and pressure-bearing gas container. The inert gas is first filtered and collected in the inert gas recovery container, and then compressed into high-pressure gas by a diaphragm compressor. After passing through the filling row (the filling row is an existing equipment, including branch pipelines, various connectors, regulators and safety devices), it is divided into several gas cylinders, and then connected to the inert gas source container 19 through several gas cylinders, and the inert gas in the inert gas protection container 21 is recycled to the inert gas source container 19. Note that only the gas in the inert gas protection container 21 is recovered here, and the waste gas mixed with standard substances is not included.

[0037] Among them, in the waste gas recovery container 22, if the recovered waste gas is harmless, it can be discharged directly. If the recovered waste gas is harmful, it needs to be discharged after being harmlessly treated by an external waste gas treatment device.

[0038] Wherein, the constant temperature chamber 12 is a sealed cabin with thermal insulation materials attached to the outside, preferably with a cylindrical design, and a temperature sensor and a temperature control device connected to the control system are arranged in the constant temperature chamber 12 (for example, the temperature control device is a heating element connected to the control system, and the heating element can be a heat pipe structure, which uses the gas-liquid phase change principle to well suppress temperature fluctuation), and the control system and the temperature control device can control the internal temperature of the constant temperature box 24 and the constant temperature chamber 12 to a set value. A plurality of permeation tubes 13 are arranged in the constant temperature chamber 12, and the permeation tubes 13 are connected to the automatic weighing module 11, and the automatic weighing module 11 can use a high-precision electronic scale. The automatic weighing module 11 can weigh the mass loss of the permeation tube 13 online at regular intervals, that is, the mass of the standard substance b that permeates and volatilizes from the permeation tube 13, and send the mass data of the standard substance b that permeates from the permeation tube 13 to the host computer, and the host computer calculates the component concentration of the standard substance b in the calibration gas output by the gas mixer 14 accordingly.

[0039] Embodiment 2

[0040] like Figure 5 As shown, a calibration method for a calibration device for a trace gas analyzer described in Embodiment 1 dilutes standard substance a and standard substance b as calibration gas, comprising the following steps:

[0041] Step 1: Input the type, concentration and flow rate of the calibration gas to be prepared, the information of the permeation tube 13, the standard material cylinder 3 and the standard material in the permeation tube 13 (the standard material includes a volatile solid or liquid standard material a, and a gaseous standard material b) and other parameters into the host computer program module.

[0042] Step 2: Start the calibration device for the trace gas analyzer, and the host computer controls the constant temperature box 24 to adjust to the working temperature required for calibration.

[0043] Step 3, after the inert gas in the inert gas source container 19 is purified by the primary purifier 1 and the two-way secondary purifier 2, it enters the electronic pressure controller three 6 and the electronic pressure controller four 7 respectively, and at the same time, the inert gas enters the inert gas protection container 21 to protect the electronic pressure controller therein, and the inert gas in the inert gas protection container 21 enters the inert gas source container 19 through the inert gas recovery module 20 for recycling and cost saving;

[0044] One path of inert gas enters flow control element 2 9 from electronic pressure controller 3 6, and then enters constant temperature chamber 12 from flow control element 2 9; another path of inert gas enters flow control element 3 10 from electronic pressure controller 4 7, and then enters gas mixer 14 from flow control element 3 10; gaseous standard substance a enters electronic pressure controller 2 5 from standard substance gas cylinder 3, and then enters flow control element 1 8 from electronic pressure controller 2 5, and finally enters gas mixer 14 from flow control element 1 8; solid and liquid standard substance b evaporates into gas from permeation tube 13 and enters constant temperature chamber 12, standard substance b is mixed with inert gas in constant temperature chamber 12, and then enters gas mixer 14;

[0045] The mixed calibration gas enters the trace gas analyzer 25 to be calibrated from the gas mixer 14 through the flow regulator 1 15. The mixed calibration gas enters the intelligent diagnosis module 23 from the gas mixer 14 through the flow regulator 2 16. The calibration gas output from the intelligent diagnosis module 23 enters the waste gas recovery container 22 as waste gas discharge.

[0046] Step 4, the automatic weighing module 11 automatically weighs the mass of the standard substance b that permeates from the permeation tube 13 during a certain period of time, and transmits it to the host computer. The volatilization rate of the standard substance b is determined by the permeability value (μg / min) of the permeation tube 13; the intelligent diagnosis module 23 monitors the concentration of the calibration gas output by the gas mixer 14 to obtain diagnostic data, and transmits it to the host computer.

[0047] In the above process, under the control of the host computer, the thermostatic box 24 and the thermostatic chamber 12 provide a constant temperature field for the permeation tube 13 according to the set volatilization temperature, and the automatic weighing module 11 automatically weighs the volatilization amount of the standard substance b during the permeation process and sends it to the host computer for calculation. In the above process, the thermostatic box 24 always controls the temperature of the components susceptible to temperature fluctuations at about 35°C.

[0048] Step 5. The host computer automatically calculates the component concentrations of the standard substance a and the standard substance b in the calibration gas according to the received data and the pre-stored parameters; sends control commands according to the calculation results, and automatically adjusts the pressure values ​​of the electronic pressure controller 1 4, the electronic pressure controller 2 5, the electronic pressure controller 3 6 and the electronic pressure controller 4 7, adjusts the temperature value of the constant temperature box 24, and adjusts the flow values ​​of the flow regulator 1 15 and the flow regulator 2 16 until the component concentrations of the standard substance a and the standard substance b in the calibration gas meet the calibration requirements.

[0049] In the second embodiment of the present invention, the constant temperature chamber 12 supports the installation of multiple permeation tubes 13 of different models and specifications, and the automatic weighing module 11 weighs the mass of gas volatilized through the permeation tube 13 within a certain time interval, and transmits the data to the host computer for calculation. For gaseous standard substances that are not suitable for permeation tubes 13, standard substance cylinders 3 can also be used to directly transport them to the gas mixer 14, and after sufficient mixing, a multi-component mixed calibration gas can be obtained, which can simultaneously calibrate multiple components of the trace gas analyzer 25 to be calibrated.

[0050] Since the gas flow rate is extremely small in the trace gas test, the pressure difference before and after the gas passes through the sharp hole 18 is negligible, and it can be considered that the pressure at each location downstream of the sharp hole 18 is equal to the pressure indication displayed by the previous electronic pressure controller.

[0051] The upper computer performs calculations as follows:

[0052] The standard substance in the standard substance cylinder 3 is recorded as "a", and the other standard substance in the permeation tube 13 is recorded as "b". More standard substance components can also be mixed, and the calculation method is similar.

[0053] The host computer performs calculations involving the following variables:

[0054] q——gas flow rate, mL / min;

[0055] p——gas pressure, kPa (controlled by an electronic pressure controller, a known quantity);

[0056] n a ——Standard value of bottled a gas standard substance (given at the time of leaving the factory, known quantity), μmol / mol;

[0057] N a ——Concentration of component a in the calibration gas output by the gas mixer 14, μmol / mol;

[0058] x b ——Permeability value of substance b relative to permeation tube 13 at nominal temperature (known quantity), μg / min;

[0059] N b ——Concentration of component b in the calibration gas output by the gas mixer 14, μmol / mol;

[0060] M 载 ——Molar mass of inert gas (known quantity depending on the source of inert gas), g / mol;

[0061] M b ——b molar mass of the substance (based on the type of substance, known amount), g / mol;

[0062] ρ b ——Nominal temperature, P 6 b gas density under pressure (can be measured experimentally in advance), g / mL;

[0063] q 8 =(P 5 -P 4 )×k

[0064] q 9 =(P 6 -P 4 )×k

[0065] q 10 =(P 7 -P 4 )×k

[0066]

[0067] If it is a mixed component of standard substances a and b, the denominator is changed to q8+q9+q10.

[0068]

[0069] Similarly, if it is a mixed component of standard substances a and b, the denominator in brackets will be changed to "q8+q9+q10".

[0070] The numbers 4, 5, 6, 7, 8, 9, and 10 in the above formula respectively correspond to the components corresponding to the figure marks in the first embodiment.

[0071] The conversion factor k is measured experimentally, and the measurement method of k is as follows:

[0072] Equipment used: pVTt method gas flow standard device (10L, China University of Metrology), pressure regulating valve (R14SL, Shanghai Jierui), back pressure valve (R78SL, Shanghai Jierui).

[0073] like Figure 6 As shown, by adjusting the pressure regulating valve and the back pressure valve and reading the data of the electronic pressure gauge, the pressure difference between the upstream and downstream of the flow control component is obtained; the gas flow is measured by the pVTt method gas flow standard device; different pressure differences and gas flow data are plotted to obtain the coefficient k under different flow requirements. Different pressure difference and gas flow curves are related to pipeline parameters, gas types, etc.

[0074] In the embodiments of the present invention, technical features that are not described in detail are all existing technologies or conventional technical means and will not be described in detail here.

[0075] Finally, it should be noted that the above embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them, and the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any technician familiar with the technical field can modify the technical solutions recorded in the above embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be covered within the protection scope of the present invention.

Claims

1. A calibration device for a trace gas analyzer, comprising a sealed standard substance gas cylinder (3), an inert gas source container (19), an inert gas protection container (21), a thermostatic box (24) and an exhaust gas recovery container (22), characterized in that: The inert gas protection container (21) is provided with an electronic pressure controller 1 (4), an electronic pressure controller 2 (5), an electronic pressure controller 3 (6) and an electronic pressure controller 4 (7); the thermostatic box (24) is provided with a flow control component 1 (8), a flow control component 2 (9), a flow control component 3 (10), a constant temperature chamber (12), an automatic weighing module (11) and a gas mixer (14); the constant temperature chamber (12) is provided with a plurality of permeation tubes (13), and the permeation tubes (13) are connected to the automatic weighing module (11); the standard substance cylinder (3) is connected to the gas mixer (14) via the electronic pressure controller 2 (5) and the flow control component 1 (8); the inert gas source container (19) is respectively connected to the inert gas recovery module (20), the inert gas protection container (21), the electronic pressure controller 3 (6) and the electronic pressure controller 4 (7); The electronic pressure controller 4 (7) is connected to the inert gas recovery module (20) and the inert gas protection container (21). The electronic pressure controller 3 (6) is connected to the flow control component 2 (9), the constant temperature chamber (12) and the gas mixer (14) in sequence. A valve is arranged between the constant temperature chamber (12) and the gas mixer (14). The electronic pressure controller 4 (7) is connected to the flow control component 3 (10) and the gas mixer (14) in sequence. The gas mixer (14) is connected to the electronic pressure controller 1 (4) and the waste gas recovery container (22) in sequence. The gas mixer (14) is respectively connected to the intelligent diagnosis module (23) and the trace gas analyzer (25) to be calibrated. The intelligent diagnosis module (23) is connected to the waste gas recovery container (22). The automatic weighing module (11) and the intelligent diagnosis module (23) are respectively electrically connected to the host computer.

2. A calibration device for a trace gas analyzer according to claim 1, characterized in that: The flow control member 1 (8), the flow control member 2 (9) and the flow control member 3 (10) all include a VCR joint (17) and a sharp hole (18). The sharp hole (18) is embedded in the inner cavity of the VCR joint (17). The diameter in the middle of the sharp hole (18) is smaller than the diameter at both ends.

3. A calibration device for a trace gas analyzer according to claim 2, characterized in that: A flow regulator 1 (15) is arranged between the gas mixer (14) and the intelligent diagnosis module (23), and a flow regulator 2 (16) is arranged between the gas mixer (14) and the trace gas analyzer (25) to be calibrated.

4. The calibration device for a trace gas analyzer according to claim 1, characterized in that: The inert gas source container (19) is connected to a primary purifier (1), and the primary purifier (1) is respectively connected to a pair of secondary purifiers (2), and the pair of secondary purifiers (2) are respectively connected to an electronic pressure controller three (6) and an electronic pressure controller four (7) via a three-way pipe joint.

5. The calibration device for a trace gas analyzer according to claim 1, characterized in that: The intelligent diagnosis module (23) is an online continuous gas monitoring device based on the principle of cavity enhanced absorption spectroscopy.

6. The calibration device for a trace gas analyzer according to claim 1, characterized in that: The inert gas recovery module (20) comprises an inert gas recovery container, a diaphragm compressor, a filling row and a plurality of gas cylinders.

7. A calibration method for a trace gas analyzer, characterized in that: The calibration device for a trace gas analyzer as claimed in claim 3 comprises the following steps: The upper computer controls the thermostat (24) to adjust to the working temperature required for calibration; the standard substance and the purified inert gas are mixed in the gas mixer (14) to form the calibration gas; the calibration gas enters the trace gas analyzer (25) to be calibrated through the first flow regulator (15) in one way; the calibration gas enters the intelligent diagnosis module (23) through the second flow regulator (16) in another way; the diagnostic data obtained by the intelligent diagnosis module (23) is transmitted to the upper computer; the calibration gas output from the intelligent diagnosis module (23) enters the waste gas recovery container (22) as waste gas; the upper computer automatically calculates the component concentration of the standard substance in the calibration gas according to the received data and the pre-stored parameters, sends a control command according to the calculation result, and automatically adjusts the pressure value of the electronic pressure controller, adjusts the temperature value of the thermostat (24), and adjusts the flow values ​​of the first flow regulator (15) and the second flow regulator (16) until the component concentration of the standard substance in the calibration gas reaches the calibration requirement.

8. A calibration method for a trace gas analyzer according to claim 7, characterized in that: If the standard material only includes the gaseous standard material a, the standard material a is loaded into the standard material gas cylinder (3), and the valve between the constant temperature chamber (12) and the gas mixer (14) is closed; if the standard material only includes the solid-liquid standard material b, the standard material gas cylinder (3) is not installed, and the standard material b is loaded into the permeation tube (13), and the standard material b is volatilized into gas and enters the constant temperature chamber (12) from the permeation tube (13), and the standard material b is mixed with the inert gas in the constant temperature chamber (12) and enters the gas mixer (14), and the automatic weighing module (11) automatically weighs the mass of the standard material b volatilized from the permeation tube (13) at a certain interval and transmits it to the host computer; if the standard material includes both the gaseous standard material a and the solid-liquid standard material b, the standard material a is loaded into the standard material gas cylinder (3), the standard material b is loaded into the permeation tube (13), and the valve between the constant temperature chamber (12) and the gas mixer (14) is opened.

9. A calibration method for a trace gas analyzer according to claim 7, characterized in that: The type, concentration and flow rate of the calibration gas to be prepared, the information of the permeation tube (13), and the information of the standard substance in the standard substance cylinder (3) and the permeation tube (13) are input into the upper computer program module in advance.

10. A calibration method for a trace gas analyzer according to claim 7, characterized in that: The temperature of the thermostat (24) is controlled at 35°C.

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