A synchronous measurement device and test method for multi-channel gas concentration sensors

Abstract

The present invention belongs to the field of instrumentation, and specifically relates to a multi-channel gas concentration sensor synchronization measurement device and a test method thereof. The test device includes a high-pressure storage tank, a buffer tank, an air pressure sensor, a switch valve, a first balancing valve, a fast switching module, a vacuum pump, a sampling tube, an exhaust pipe and a host computer. The switch valve is used to switch the on-off of the air intake channel between the buffer tank and the high-pressure storage tank. The first balancing valve is used to adjust the opening of the exhaust channel between the buffer tank and the atmosphere. The fast switching module is used to adjust the gas type at the gas concentration sensor. The host computer coordinates the operating status of each component, and then provides a synchronous, stable and uniform gas detection environment for each gas concentration sensor through the buffer tank, and tests the difference in response time of each gas concentration sensor. The scheme of the present invention can realize automated measurement, and can realize more accurate environmental control, and the accuracy and reliability of the measured synchronization data are higher.

Description

Technical Field

[0001] The invention belongs to the field of instruments and meters, and in particular relates to a synchronization measuring device for multi-channel gas concentration sensors and a testing method thereof. Background Art

[0002] In the existing aircraft fire extinguishing system effectiveness verification standards, 12 sampling points need to be arranged in the protected cabin of the aircraft. For example, the qualification criterion of the Halon 1301 fire extinguishing system is "after the fire extinguishing system releases the fire extinguishing agent, the fire extinguishing agent concentration at the 12 sampling points reaches 6% and is maintained for at least 0.5s". The relevant airworthiness standards for transport aircraft also stipulate that in each designated fire zone, the concentration of the fire extinguishing agent sprayed by the fire extinguishing system should reach the minimum value that can extinguish the fire and prevent re-ignition. The gas fire extinguishing agent concentration analyzer is a key equipment for the airworthiness verification of the fire extinguishing system. In addition to measurement accuracy, response time and time synchronization of multi-channel measurements are also important performance indicators of the analyzer, which have a greater impact on the time criterion.

[0003] The gas fire extinguishing agent concentration analyzer is a type of gas concentration sensor. It is designed based on the pressure difference principle and is different from the mainstream semiconductor, electrochemical, and non-dispersive infrared technology gas concentration sensors. This type of sensor has the characteristics of a wide measurement range (up to 100%), high accuracy, good stability, and the ability to achieve multi-channel simultaneous measurement. It is suitable for aircraft gas fire extinguishing agent concentration measurement.

[0004] According to the previous content, the verification system for the effectiveness of the fire extinguishing system has high requirements for the consistency of the response time of the gas concentration sensor used. Only when the response characteristics of the gas concentration sensors measuring each sampling point are highly synchronized can the final verification result be guaranteed to be reliable. However, there are few studies on the synchronization of the response time of multi-channel measurements of gas concentration sensors in the prior art. In order to effectively evaluate the synchronization of the response characteristics of different gas concentration sensors, technicians usually install multiple sensors in the same measurement space, and the technicians manually control and perform multiple response-recovery experiments. The operation process of this synchronization test method is cumbersome, and it is difficult to ensure the consistency of the sensor detection environment, and the reliability of the measurement results is insufficient. Summary of the invention

[0005] In order to solve the defects of complicated operation and insufficient reliability in the synchronous measurement solution of multiple gas concentration sensors provided in the prior art, the present invention provides a synchronous measurement device of multiple gas concentration sensors and a test method thereof.

[0006] The technical solution provided by the present invention is:

[0007] A multi-channel gas concentration sensor synchronization measurement device is used to test and evaluate the synchronization of the response characteristics of multiple gas concentration sensors. The measurement device includes: a high-pressure storage tank, a buffer tank, an air pressure sensor, a switch valve, a first balancing valve, a fast switching module, a vacuum pump, multiple sampling tubes, multiple exhaust pipes and a host computer.

[0008] The buffer tank is connected to a high-pressure storage tank storing compressed sample gas through a switch valve, and is connected to the atmosphere through a first balancing valve. An air pressure sensor is arranged in the buffer tank. A fast switching module consisting of a plurality of circumferentially arranged three-way solenoid valves is provided on the tank wall of the buffer tank. Each three-way solenoid valve includes two air inlet ends and one air outlet end. One of the air inlet ends is connected to the atmosphere, and the other air inlet end is connected to the inner cavity of the buffer tank. The air outlet ends of each three-way solenoid valve are connected to the air inlet ends of each gas concentration sensor to be measured through a multi-channel sampling pipe. The air outlet end of the gas concentration sensor is connected to a vacuum pump through a multi-channel exhaust pipe. The host computer is used to obtain the detection data of the air pressure sensor and the gas concentration sensor, and to adjust the operating status of the switch valve, the first balancing valve, the fast switching module and the vacuum pump. The diameter and length of each sampling pipe are the same, and the diameter and length of each exhaust pipe are the same.

[0009] As a further improvement of the present invention, a pressure reducer is further provided at the exhaust port of the high-pressure storage tank, and the pressure reducer is used to adjust the flow rate of the sample gas discharged from the high-pressure storage tank.

[0010] As a further improvement of the present invention, the exhaust port of the high-pressure storage tank is connected to the gas inlet of the buffer tank through a three-way pipe, and the other port of the three-way pipe is connected to the atmosphere outside the buffer tank through a second balancing valve. The second balancing valve of the present invention serves as a redundancy of the first balancing valve and is used to adjust the opening of the exhaust passage between the buffer tank and the atmosphere.

[0011] As a further improvement of the present invention, the multi-channel gas concentration sensor synchronization measurement device also includes a gas collecting device, which is respectively connected to the exhaust port of the vacuum pump and the gas outlet of the buffer tank. The gas collecting device is used to collect sample gas discharged from the vacuum pump and the buffer tank during the execution of the test task.

[0012] As a further improvement of the present invention, the air pressure sensor includes a meter head and a sensitive element, wherein the sensitive element is inserted into the inner cavity of the buffer tank; the meter head is located outside the buffer tank and is used to display the pressure data detected by the sensitive element.

[0013] and / or

[0014] The host computer also includes a display module, which is used to display the progress, data and results of the synchronization test tasks of each gas concentration sensor.

[0015] As a further improvement of the present invention, each three-way solenoid valve in the fast switching module synchronously switches the connection state between the air outlet and one of the air inlet ends according to the instruction issued by the host computer.

[0016] As a further improvement of the present invention, a multi-port manifold block is connected to the air inlet of the vacuum pump; each exhaust pipe is connected to each air hole on the manifold block;

[0017] and / or

[0018] The number of air holes of the manifold block corresponds to the number of sampling pipes and exhaust pipes and the number of three-way solenoid valves.

[0019] The present invention also includes a method for testing the synchronization of a gas concentration sensor, which utilizes the aforementioned multi-channel gas concentration sensor synchronization measurement device to automatically test and evaluate the synchronization of multiple gas concentration sensors. The measurement method includes the following steps:

[0020] S1: Connect each gas concentration sensor to be tested in the current batch to the multi-channel gas concentration sensor synchronization measurement device, and preset the pressure peak value in the host computer P max , Balance pressure P ba , and the maximum number of cycles n .

[0021] S2: The host computer performs equipment initialization: At this time, the vacuum pump, the first balancing valve and the switch valve are closed, and each three-way solenoid valve in the fast switching module is switched to the first state in which the gas concentration sensor is connected to the buffer tank.

[0022] S3: After initialization is completed, the host computer issues control instructions and executes a synchronization test cycle in the following order:

[0023] S31: Turn on the vacuum pump to evacuate the buffer tank to a vacuum state.

[0024] S32: Switch each three-way solenoid valve in the fast switching module to the second state where the gas concentration sensor is connected to the atmosphere. Close the first balancing valve and the vacuum pump, and open the switch valve until the pressure in the buffer tank reaches the preset pressure peak. P max .

[0025] S33: Turn on the vacuum pump and the first balancing valve, switch each three-way solenoid valve in the fast switching module to the first state, and then adjust the opening of the first balancing valve until the pressure in the buffer tank stabilizes at the preset balancing pressure. P ba .

[0026] S34: Switch each three-way solenoid valve in the fast switching module to the second state, and obtain detection data of each gas concentration sensor.

[0027] S35: When the detection values ​​of each gas concentration sensor return to zero, each three-way solenoid valve in the fast switching module is synchronously switched to the first state, the detection data of each gas concentration sensor is recorded, and the response curve of the gas concentration sensor under the current test cycle is plotted.

[0028] S4: Switch each three-way solenoid valve in the fast switching module to the second state, so that the detection value of each gas concentration sensor is reset to zero; then repeat steps S2-S3 until the preset maximum number of cycles is reached. n .

[0029] S5: According to the response curves of the gas concentration sensors obtained in each test cycle, the synchronization of the gas concentration sensors is evaluated, and the synchronization deviation of the gas concentration sensors in the current batch is calculated.

[0030] As a further improvement of the present invention, in step S35, the response time of each gas concentration sensor is The calculation formula is:

[0031]

[0032] In the above formula, t 1 indicates the moment when the reading of each gas concentration sensor starts to rise from 0 in each test cycle; t 2 indicates the moment when the reading of each gas concentration sensor rises to the maximum value.

[0033] In step S5, the synchronization deviation of each gas concentration sensor in the current batch The calculation formula is as follows:

[0034]

[0035] In the above formula, Indicates i Synchronicity deviation of the wheel test cycle, Indicates i The maximum value of the response time of each gas concentration sensor in the round test cycle; Indicates i The minimum value of the response time of each gas concentration sensor in the round test cycle; n Indicates the preset maximum number of loops.

[0036] The technical solution provided by the present invention has the following beneficial effects:

[0037] The present invention provides a device and a testing method specifically used for testing and evaluating the synchronization of multiple gas concentration sensors. Compared with the existing technology, this scheme can effectively control the consistency of the detection environment of each gas sensor and can synchronously switch the detection environment, thereby greatly improving the accuracy and reliability of the evaluation results.

[0038] The solution of the present invention can realize automated measurement when testing the difference in response time of multiple gas concentration sensors, without the need for testers to manually adjust the operating status of the equipment. This can not only overcome the errors caused by the asynchrony of manual operation by testers, but also greatly reduce the workload of testers.

[0039] The solution of the present invention is very suitable for synchronous testing of gas extinguishing agent concentration analyzers in aircraft fire verification systems, and can assist in selecting sensors that meet the requirements, or correct the response performance of sensors, thereby improving the reliability of the verification system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic diagram of the overall structure of the synchronous measurement device for multiple gas concentration sensors provided in Example 1 of the present invention.

[0041] Figure 2 This is a schematic structural diagram of the high-pressure storage tank in the measuring device provided in Example 1 of the present invention.

[0042] Figure 3 This is a schematic diagram of the structure of the buffer tank in the measuring device of Example 1 of the present invention.

[0043] Figure 4 This is a schematic structural diagram of the buffer tank bottom perspective of Example 1 of the present invention.

[0044] Figure 5 It is an assembly diagram of the buffer tank, the air pressure sensor, the switch valve, the first balancing valve, and the fast switching module in the test box in Example 1 of the present invention.

[0045] Figure 6 This is a functional principle diagram of each three-way solenoid valve in the fast switching module of Example 1 of the present invention.

[0046] Figure 7 Schematic diagram of the structure of the vacuum pump in Example 1 of the present invention.

[0047] Figure 8 This is a flow chart of the steps of the method for testing the synchronization of the gas concentration sensor provided in Example 2 of the present invention.

[0048] Fig. 9 A typical response curve measured for a gas concentration sensor.

[0049] Fig.10 This is a schematic diagram of the assembly of components such as a buffer tank after adding a second balancing valve provided in Example 4 of the present invention.

[0050] The markings in the figure are: 1. High-pressure storage tank; 2. Test box; 3. Sampling tube; 4. Exhaust tube; 5. Vacuum pump; 6. Host computer; 7. Buffer tank; 8. Switch valve; 9. First balancing valve; 10. Quick switching module; 11. Pressure reducer; 12. Air pressure sensor; 13. Three-way pipe; 14. Second balancing valve; 51. Manifold block; 61. Display module; 71. Gas inlet; 72. Gas outlet; 73. Gas sampling port; 74. Mounting hole; 75. Support foot; 100. Gas concentration sensor. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0052] Example 1

[0053] This embodiment provides a multi-channel gas concentration sensor 100 synchronization measurement device, which is used to test and evaluate the synchronization of the response time of multiple gas concentration sensors 100. Specifically, Figure 1 As shown, the measuring device includes: a high-pressure storage tank 1, a buffer tank 7, an air pressure sensor 12, a switch valve 8, a first balancing valve 9, a fast switching module 10, a vacuum pump 5, a multi-channel sampling pipe 3, a multi-channel exhaust pipe 4, and a host computer 6. The buffer tank 7, the air pressure sensor 12, the switch valve 8, the first balancing valve 9, and the fast switching module 10 are installed in a test box 2.

[0054] In the multi-channel gas concentration sensor synchronization measurement device of the present embodiment, the host computer 6 is electrically connected to the switch valve 8, the first balancing valve 9, the fast switching module 10, the vacuum pump 5, the air pressure sensor 12 and the gas concentration sensor 100 to be tested in the test box 2. And the corresponding control program is designed in the host computer 6, so that the host computer 6 can adjust the operating status of the switch valve 8, the switch valve 8, the first balancing valve 9, the fast switching module 10 and the vacuum pump 5 according to the program, and obtain the detection data of the air pressure sensor 12 and the gas concentration sensor 100. Then support the realization of the synchronization of the response time of each gas concentration sensor 100 for automated testing and evaluation, thereby greatly reducing the workload of the tester. In particular, the host computer 6 also includes a display module 61, which is used to display the process, data and results of the synchronization test task of the gas concentration sensor 100.

[0055] In detail, Figure 1 In the multi-channel gas concentration sensor synchronization measurement device shown, the high-pressure storage tank 1 is used to store the compressed gas of the sample gas measured by the gas concentration sensor 100. The high-pressure storage tank 1 is connected to the gas inlet 71 of the buffer tank 7, and the sample gas is continuously transported into the buffer tank 7 during the test. Figure 2 As shown, in a more optimized solution, a pressure reducer 11 is further provided at the exhaust port of the high-pressure storage tank 1, and the pressure reducer 11 is used to adjust the flow rate of the sample gas discharged from the high-pressure storage tank 1. In practical applications, considering that different sample gases have different requirements for storage containers, the high-pressure storage tank 1 of this embodiment can select a suitable pressure container according to the type of the gas concentration sensor 100 to be tested.

[0056] The buffer tank 7 is essentially a pressure vessel. The buffer tank 7 provided in this embodiment is used to buffer the sample gas discharged from the high-pressure storage tank 1. After the concentration and pressure of the sample gas are kept uniform and stable, it is synchronously transported to each gas concentration sensor 100 to be tested, thereby ensuring the consistency of the detection environment of each gas concentration sensor 100. Based on the pursuit of consistency of the released sample gas, such as Figure 3 and Figure 4 As shown, in this embodiment, the buffer tank 7 is designed to be a capsule-shaped cylindrical type. In the best solution, a gas inlet 71 is provided at the top of the buffer tank 7, a gas outlet 72 is provided at the bottom, and a gas sampling port 73 for releasing sample gas to each gas concentration sensor 100 is evenly distributed in a ring along the side of the tank wall. Among them, the gas inlet 71, the gas outlet 72 and each gas sampling port 73 in the buffer tank 7 are all connected to the inner cavity of the tank body, the gas inlet 71 of the buffer tank 7 is used to connect to the high-pressure storage tank 1, and the gas outlet 72 is connected to the atmosphere outside the tank body.

[0057] The side wall of the buffer tank 7 provided in this embodiment may also be provided with a mounting hole 74 for mounting the air pressure sensor 12, and the position of the mounting hole 74 is not limited. Four supporting feet 75 are also provided at the bottom of the buffer tank 7 in this embodiment, and the supporting feet 75 may be fixedly mounted through the reserved through holes, or universal pulleys may be installed to facilitate the movement of the device.

[0058] In the typical solution illustrated in the present embodiment, for the test scenario of the gas extinguishing agent concentration analyzer, 12 gas sampling ports 73 are provided on the side wall of the buffer tank 7 to form 12 independent measurement channels. In other embodiments, the number of measurement channels in the multi-channel gas concentration sensor synchronization measurement device can also be flexibly set according to the actual application scenario.

[0059] Specifically, the gas inlet 71 at the top of the buffer tank 7 is a Rc1 / 2in thread, the gas outlet 72 at the bottom is a Rc 1 / 2in thread, the mounting hole 74 at the upper middle part and the pressure sensor 12 is a Rc1 / 2in thread, and the annular gas sampling port 73 is a Rc1 / 4in thread.

[0060] like Figure 5 As shown, the switch valve 8 is connected to the gas inlet 71 of the buffer tank 7, and the switch valve 8 is used to switch the on and off of the air intake channel between the buffer tank 7 and the high-pressure storage tank 1. The first balancing valve 9 is connected to the gas outlet 72 of the buffer tank 7, and the first balancing valve 9 is used to adjust the opening of the exhaust channel between the buffer tank 7 and the atmosphere. During the operation of the equipment, the switch valve 8 and the first balancing valve 9 are coordinated and controlled to dynamically adjust the pressure and concentration of the sample gas introduced into the buffer tank 7. The adjustment principle is as follows:

[0061] After the switch valve 8 is opened, the high-pressure gas in the high-pressure storage tank 1 will be transported to the inner cavity of the buffer tank 7. After the switch valve 8 is opened, the intake flow of the buffer tank 7 will be controlled by the pressure reducer 11 at the exhaust port of the high-pressure storage tank 1. In this state, the exhaust flow of the buffer tank 7 can be further regulated by continuing to adjust the opening of the first balancing valve 9, thereby adjusting the pressure and concentration of the sample gas in the inner cavity of the buffer tank 7. Specifically, when the intake flow is greater than the exhaust flow, the pressure and concentration of the sample gas in the sample buffer tube increase; when the intake flow is less than the exhaust flow, the pressure and concentration of the sample gas in the sample buffer tube decrease; when the intake flow is equal to the exhaust flow, the pressure and concentration of the sample gas in the sample buffer tube remain stable.

[0062] The air pressure sensor 12 is installed on the buffer tank 7 and is used to monitor the internal pressure of the buffer tank 7. In a more optimized solution of this embodiment, the air pressure sensor 12 includes a header and a sensitive element. Among them, the sensitive element is inserted into the inner cavity of the buffer tank 7 along the mounting hole 74 in the buffer tank 7, and the header is located outside the buffer tank 7. The header is used to display the pressure data detected by the sensitive element. The header in this embodiment can be a pointer type or a digital display. The function of the header is to facilitate the tester to intuitively observe the air pressure in the buffer tank 7. It should be specially noted that: the host computer 6 of this embodiment is directly electrically connected to the data processing module in the air pressure sensor 12, and then obtains the detection data of the air pressure sensor 12. The data acquisition process of the host computer 6 does not need to rely on the display function of the header. The header is only used to visualize the detection results.

[0063] In this embodiment, the fast switching module 10 includes a plurality of three-way solenoid valves corresponding to the number of the gas sampling ports 73, such as Figure 6As shown, each three-way solenoid valve is installed at one of the gas sampling ports 73 of the buffer tank 7. Among them, the three-way solenoid valve includes two air inlet ends P1, P2 and an air outlet end A. One of the air inlet ends P1 of the three-way solenoid valve is connected to the inner cavity of the buffer tank 7, and the other air inlet end P2 is connected to the atmosphere outside the buffer tank 7; the air outlet end A is used to connect the gas concentration sensor 100 to be tested. Therefore, the three-way solenoid valve in the fast switching module 10 provided in this embodiment actually has two working states: in the first state, the P1 end is connected to the A end, at this time, the sample gas in the sample buffer tube can enter the gas concentration sensor 100 through the three-way solenoid valve. In the second state, the P2 end is connected to the A end. At this time, the atmosphere outside the sample buffer tube can enter the gas concentration sensor 100 through the three-way solenoid valve. The fast switching module 10 of this embodiment is used to synchronously switch the working state of each three-way solenoid valve according to the instruction of the host computer 6.

[0064] In this embodiment, each connected sampling tube 3 and exhaust pipe constitutes a detection channel for measuring the response characteristics of the gas concentration sensor 100; the gas concentration sensor 100 is located between the sampling tube 3 and the exhaust pipe. Figure 1 As shown, one end of each sampling tube 3 is connected to the outlet of each three-way solenoid valve in the fast switching module 10, and the other end is connected to the inlet of each gas concentration sensor 100 to be tested; one end of each exhaust pipe 4 is connected to the outlet of each gas concentration sensor 100 to be tested, and the other end is connected to the air inlet of the vacuum pump 5. The vacuum pump 5 is used to extract the gas discharged from the outlet of the fast switching module 10 and make it flow through each gas concentration sensor 100 to be tested.

[0065] In each detection channel, the vacuum pump 5 can generate negative pressure on the outlet side of the gas concentration sensor 100, and then "suck" the sample gas synchronously discharged under the control of the fast switching module 10 to each gas sensor. In the scheme of this embodiment, since each three-way solenoid valve is switched synchronously, the gas in each sampling tube 3 is synchronously discharged. In order to ensure that the sample gas released by the buffer tank 7 can also reach each gas sensor synchronously, the diameter and length of each sampling tube 3 in this embodiment are the same. In a more optimized scheme, in order to keep the negative pressure state at the outlet of each gas concentration sensor 100 consistent, the diameter and length of each exhaust pipe 4 are the same, and as Figure 7 As shown, a multi-port manifold block 51 is connected to the air inlet of the vacuum pump 5; each exhaust pipe 4 is connected to each air hole on the manifold block 51. The number of air holes on the manifold block 51 in this embodiment corresponds to the number of sampling pipes 3 and exhaust pipes 4 and the number of three-way solenoid valves.

[0066] In addition, it is necessary to further explain that the synchronous measurement device for multiple gas concentration sensors provided in this embodiment is mainly designed for the gas extinguishing agent concentration analyzer designed based on the pressure difference principle mentioned above. Of course, the synchronous measurement device can also be used to perform performance consistency tests on other types of gas concentration sensors 100. When the synchronous measurement device is used to test other gas concentration sensors 100, it is only necessary to add an independent test chamber between each sampling tube 3 and the exhaust tube 4, and place the gas concentration sensor 100 to be tested in the test chamber.

[0067] Example 2

[0068] Based on the hardware solution of the multi-channel gas concentration sensor synchronization measurement device provided in Example 1, this embodiment further provides a method for testing the synchronization of a gas concentration sensor 100. This testing method can utilize the multi-channel gas concentration sensor synchronization measurement device of Example 1 to realize automatic testing and evaluation of the synchronization of multiple gas concentration sensors 100.

[0069] Specifically, Figure 8 As shown, the measurement method provided in this embodiment includes the following steps:

[0070] S1: The gas concentration sensors 100 to be tested in the current batch are Figure 1 The method is connected to the multi-channel gas concentration sensor synchronization measurement device, so that one end of each gas concentration sensor 100 is connected to the sampling pipe 3, and the other end is connected to the exhaust pipe 4.

[0071] Then preset the peak pressure of the current test round in the host computer 6 P max , Balance pressure P ba , and the maximum number of cycles n Among them, the peak pressure P max The maximum pressure when the sample gas is pre-filled in the buffer tank 7 during the test task; the balance pressure P ba During the test, in order to maintain uniform gas concentration at each gas concentration sensor 100, the pressure value in the buffer tank 7 should be maintained. The maximum number of cycles is the number of test cycles that need to be repeatedly executed in the test task. The multi-channel gas concentration sensor synchronization measurement device provided in this embodiment supports automated multi-round testing to eliminate accidental errors in the measurement results.

[0072] S2: The host computer 6 performs equipment initialization: At this time, the vacuum pump 5, the first balancing valve 9 and the switch valve 8 are closed, and each three-way solenoid valve in the fast switching module 10 is switched to the first state in which the gas concentration sensor 100 is connected to the buffer tank 7.

[0073] In the initialization state, the two valves at the gas inlet 71 and the gas outlet 72 of the buffer tank 7 are closed. At this time, the inner cavity of the buffer tank 7 can only be connected to the vacuum pump 5 through the three-way solenoid valve in the fast switching module 10, which can lay the foundation for emptying the gas in the buffer tank 7 through the vacuum pump 5 in the subsequent process.

[0074] S3: After the initialization is completed, the host computer 6 issues a control instruction and executes a synchronization test cycle in the following order:

[0075] S31: Turn on the vacuum pump 5 to evacuate the buffer tank 7 to a vacuum state.

[0076] In this embodiment, the purpose of evacuating the buffer tank 7 at the beginning of the experiment is to exhaust the possible impurity gases therein, which can ensure that after the sample gas is subsequently filled in, the buffer tank 7 only contains the sample gas, thereby avoiding the impurity gas from interfering with the measured response curve of the gas concentration sensor 100.

[0077] S32: Switch each three-way solenoid valve in the fast switching module 10 to the second state where the gas concentration sensor 100 is connected to the atmosphere. Close the first balancing valve 9 and the vacuum pump 5, and open the switch valve 8 until the pressure in the buffer tank 7 reaches the preset pressure peak. P max .

[0078] At this stage, the gas sampling port 73 and the gas outlet 72 of the buffer tank 7 are closed, and the inner cavity of the buffer tank 7 is connected to the high-pressure storage tank 1. Therefore, the sample gas in the high-pressure state in the high-pressure storage tank 1 will be continuously filled into the buffer tank 7 in the low-pressure state. At this stage, the gas pressure of the sample gas in the buffer tank 7 reaches the peak pressure. P max The test ends at this time and enters the subsequent balanced pressure debugging stage.

[0079] S33: Turn on the vacuum pump 5 and the first balancing valve 9, switch each three-way solenoid valve in the fast switching module 10 to the first state, and then adjust the opening of the first balancing valve 9 until the pressure in the buffer tank 7 stabilizes at the preset balancing pressure. P ba .

[0080] In the step, the vacuum pump 5 and the first balancing valve 9 are both opened, and the three-way solenoid valve is also switched to the first state, so the buffer tank 7 is in a superposition state of continuous inflow and continuous outflow of the sample gas. The sample gas flows in through the switch valve 8. The switch valve 8 of this embodiment maintains a constant opening in the open state, so the flow rate Q of the sample gas entering the buffer tank 7 is in The gas outflow channel in the buffer tank 7 includes two routes. The first route is directly discharged into the atmosphere through the first balancing valve 9, and the second route is discharged through the three-way solenoid valve, sampling tube 3, gas concentration sensor 100, exhaust pipe 4 in sequence and discharged by the vacuum pump 5. In the two gas outflow channels, the opening of the three-way solenoid valve remains unchanged. Therefore, the exhaust flow rate Q of the sample gas in this route is out1 The opening of the first balancing valve 9 in the other path can be freely adjusted, so the exhaust flow rate Q of the sample gas in this path is out2 In this state, the host computer 6 continuously adjusts the opening of the first balancing valve 9 and collects the detection data of the air pressure sensor 12, and then finds the value that satisfies Q through negative feedback regulation. in = Q out1 + Q out2 The gas pressure in the buffer tank 7 is controlled at a preset equilibrium pressure. P ba nearby.

[0081] After the regulation is completed, the gas concentration and pressure in the buffer tank 7 remain substantially constant, and therefore, parameters such as the flow rate and concentration of the sample gas released to each gas concentration sensor 100 can also remain consistent.

[0082] S34: Switch each three-way solenoid valve in the fast switching module 10 to the second state, and obtain detection data of each gas concentration sensor 100.

[0083] The purpose of this step is to place the gas concentration sensors 100 in an environment filled with air, so that each gas concentration sensor 100 is in a recovery state, thereby laying the foundation for synchronously switching each gas concentration sensor 100 to a detection environment filled with sample gas in the subsequent steps. In layman's terms, the purpose of this step is to place each gas concentration sensor 100 that is undergoing a response time synchronization test on the same "starting line".

[0084] S35: When the detection values ​​of each gas concentration sensor 100 return to zero, each three-way solenoid valve in the fast switching module 10 is synchronously switched to the first state, the detection data of each gas concentration sensor 100 is recorded, and the response curve of the gas concentration sensor 100 under the current test cycle is plotted.

[0085] When the readings of each gas concentration difference return to zero, it means that all gas concentration sensors 100 are in a recovery state. Therefore, when the three-way solenoid valves in the fast switching module 10 are synchronously switched to the first state, all gas concentration sensors 100 are placed in a sample gas environment of the same state at the same time. At this time, after drawing a response curve based on the detection data of each gas concentration sensor 100, the differences in the response characteristics of each gas concentration sensor 100 can be intuitively observed.

[0086] At this point, a complete synchronization test cycle is completed.

[0087] S4: Switch each three-way solenoid valve in the fast switching module 10 to the second state, so that the detection value of each gas concentration sensor 100 is reset to zero; then repeat steps S2-S3 until the preset maximum number of cycles is reached. n .

[0088] S5: According to the response curves of the gas concentration sensors 100 obtained in each test cycle, the synchronization of the gas concentration sensors 100 is evaluated, and the synchronization deviation of the gas concentration sensors 100 in the current batch is calculated. Finally, the host computer 6 will organize the data of the test process and generate an evaluation report.

[0089] The above solution provided in this embodiment is mainly used to evaluate the response time of each gas concentration sensor 100 in the same test batch. If the response times of the gas concentration sensors 100 are roughly the same, it means that the synchronization of these gas concentration sensors 100 is good and they can be applied to gas extinguishing agent concentration analyzers and other scenarios that require high sensor synchronization. On the contrary, if the response times of the gas sensors are very different, that is, the synchronization deviation If the value is larger, it means that the synchronization of the gas concentration sensors 100 is poor and they are not suitable for use in scenarios such as gas fire extinguishing agent concentration analyzers that require high sensor synchronization.

[0090] The response time of the same batch of gas concentration sensors 100 can be determined based on the response curve. Fig. 9 FIG. 1 is a typical response curve of a gas concentration sensor 100. The rising section of the curve in the figure is the response stage of the sensor, and the falling section of the curve is the recovery stage of the sensor. t Time 0 is the time when the three-way solenoid valve switches the detection environment of the gas concentration sensor 100 from the atmosphere to the sample gas during the test; t 1 represents the moment when the reading of each gas concentration sensor 100 starts to rise from 0 in the current test cycle; t 2 represents the moment when the reading of each gas concentration sensor 100 rises to the maximum value; t3 indicates the time when the measurement is ended after the readings of each gas concentration sensor 100 remain stable for a period of time in the current test cycle.

[0091] According to the response curve drawn, the response time of each gas concentration sensor 100 in this embodiment is The calculation formula is:

[0092]

[0093] Furthermore, the synchronization deviation used to evaluate the synchronization of the same batch of gas concentration sensors 100 is , is actually the maximum value of the difference between the maximum response time and the minimum response time in each round. That is, the synchronization deviation of each gas concentration sensor 100 in the current batch The calculation formula is as follows:

[0094]

[0095] In the above formula, Indicates i Synchronicity deviation of the wheel test cycle, Indicates i The maximum value of the response time of each gas concentration sensor 100 in the round test cycle; Indicates i The minimum value of the response time of each gas concentration sensor 100 in the round test cycle; n Indicates the preset maximum number of loops.

[0096] It should be noted that, in addition to evaluating the synchronization differences of the same batch of gas concentration sensors 100 according to the above process, the solution of this embodiment can also be used to calculate the difference between the response time value of each gas concentration sensor 100 and the minimum response time. According to this calculation result, each gas concentration sensor 100 can be further corrected. The work of correcting the response performance of the gas concentration sensor 100 does not belong to the content of this solution, and will not be described in detail herein.

[0097] Example 3

[0098] Embodiment 1 provides a synchronous measurement device for multiple gas concentration sensors that can realize automatic control. On this basis, this embodiment provides a simplified solution for the synchronous measurement device for multiple gas concentration sensors that needs to be manually controlled.

[0099] Specifically, the main difference between the multi-channel gas concentration sensor synchronization measurement device provided in this embodiment and the solution of Example 1 is that the product of this embodiment does not include the host computer 6. During the operation of the equipment, the operating status of the switch valve 8, the first balancing valve 9, the fast switching module 10 and the vacuum pump 5 needs to be manually operated and adjusted by the tester. The detection data of the air pressure sensor 12 and the gas concentration sensor 100 also need to be manually read and recorded by the tester. In addition, in the automation equipment solution of Example 1, the switch valve 8 and the first balancing valve 9 are both electrically controlled valves, while in the manual control solution provided in this embodiment, the switch valve 8 and the first balancing valve 9 can choose manually switched valves.

[0100] It should be particularly noted that: even in the manual operation scheme of this embodiment, in order to achieve synchronous switching of the gas environment of each measurement channel, the quick switching module 10 also needs to adopt a three-way solenoid valve. The difference is that: each three-way solenoid valve in this embodiment needs to be jointly controlled by a PLC controller, and the user can use a manual control module (such as a button or a boat-shaped switch) connected to the PLC controller to achieve one-key switching of the switch state of each three-way solenoid valve.

[0101] In the scheme of Example 1, each three-way solenoid valve in the fast switching module 10 can directly receive the control signal of the upper computer 6, or, as in the present embodiment, each three-way solenoid valve can be connected to a PLC controller, and the upper computer 6 instructions can be received through a PLC controller, and the PLC controller can send a state switching control signal to each three-way solenoid valve.

[0102] Example 4

[0103] On the basis of the scheme of Example 1, this embodiment further provides a more optimized multi-channel gas concentration sensor synchronization measurement device, the difference between this scheme and the scheme of Example 1 is: Fig.10 As shown, in this embodiment, a three-way pipe 13 is arranged at the exhaust port of the high-pressure storage tank 1, two ports of the three-way pipe 13 are respectively connected to the gas inlet 71 of the buffer tank 7 and the exhaust port of the high-pressure storage tank 1; the other port is connected to the atmosphere outside the buffer tank 7 through the second balancing valve 14.

[0104] In this solution, the second balancing valve 14 serves as a redundancy for the first balancing valve 9. At this time, when the tester needs to adjust the gas pressure and gas concentration in the buffer tank 7, it can be achieved by adjusting the opening of the first balancing valve 9 or the opening of the second balancing valve 14. When necessary (for example, when the intake flow rate is greater than the maximum exhaust flow rate of a single balancing valve), the opening of the two balancing valves can be jointly adjusted to achieve regulation.

[0105] In addition, the air flow channel controlled by the second balancing valve 14 provided in this embodiment can also allow the tester to empty or clean the inner cavity of the tank body by pumping gas into the buffer tank 7 at the end of the test task.

[0106] Example 5

[0107] On the basis of the above-mentioned embodiments, this embodiment provides a more optimized solution. Specifically, the multi-channel gas concentration sensor synchronization measurement device provided in this embodiment also includes a gas collection device. The gas collection device is connected to the exhaust port of the vacuum pump 5 and the gas outlet 72 of the buffer tank 7 respectively, and the gas collection device is used to collect the sample gas discharged from the vacuum pump 5 and the buffer tank 7 during the execution of the test task.

[0108] The reason why this embodiment provides a multi-channel gas concentration sensor synchronization measurement device with a gas collection device is mainly for the synchronization test scenario of some gas concentration sensors 100 for toxic and harmful gases. In this special scenario, the gas collection device can collect the sample gas discharged from the buffer tank 7 or the vacuum pump 5 during the test process to prevent the toxic and harmful sample gas from flowing into the atmosphere, causing pollution to the environment or endangering the life and health of the test personnel.

[0109] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for testing the synchronization of a gas concentration sensor, characterized in that: It uses a multi-channel gas concentration sensor synchronization measurement device to automatically test and evaluate the synchronization of multiple gas concentration sensors; The multi-channel gas concentration sensor synchronization measurement device comprises: a high-pressure storage tank, a buffer tank, a pressure sensor, a switch valve, a first balancing valve, a fast switching module, a vacuum pump, a multi-channel sampling pipe, a multi-channel exhaust pipe and a host computer; The buffer tank is connected to a high-pressure storage tank storing compressed sample gas through a switch valve, and is connected to the atmosphere through a first balancing valve; an air pressure sensor is arranged in the buffer tank; a fast switching module composed of a plurality of circumferentially arranged three-way solenoid valves is provided on the tank wall of the buffer tank; each three-way solenoid valve includes two air inlet ends and one air outlet end; one of the air inlet ends is connected to the atmosphere, and the other air inlet end is connected to the inner cavity of the buffer tank; the pipe diameter and length of each sampling pipe are the same, and the pipe diameter and length of each exhaust pipe are the same; the air outlet end of each three-way solenoid valve is connected to the air inlet end of each gas concentration sensor to be tested through a multi-channel sampling pipe; the air outlet end of the gas concentration sensor is connected to the vacuum pump through a multi-channel exhaust pipe; the host computer is used to obtain the detection data of the air pressure sensor and the gas concentration sensor, and adjust the operating status of the switch valve, the first balancing valve, the fast switching module and the vacuum pump; The method for testing the synchronization of the gas concentration sensor comprises the following steps: S1: Connect each gas concentration sensor to be tested in the current batch to the multi-channel gas concentration sensor synchronization measurement device, and preset the pressure peak, equilibrium pressure, and maximum number of cycles in the host computer; S2: The host computer performs equipment initialization. At this time, the vacuum pump, the first balancing valve and the switch valve are all closed, and each three-way solenoid valve in the fast switching module is switched to the first state where the gas concentration sensor is connected to the buffer tank; S3: After initialization is completed, the host computer issues control instructions and executes a synchronization test cycle in the following order: S31: Turn on the vacuum pump to evacuate the buffer tank to a vacuum state; S32: Switch each three-way solenoid valve in the fast switching module to the second state in which the gas concentration sensor is connected to the atmosphere; close the first balancing valve and the vacuum pump, and open the switch valve until the pressure in the buffer tank reaches a preset pressure peak; S33: Turn on the vacuum pump and the first balancing valve, switch each three-way solenoid valve in the fast switching module to the first state, and then adjust the opening of the first balancing valve until the pressure in the buffer tank is stabilized at a preset balancing pressure; S34: switching each three-way solenoid valve in the fast switching module to the second state, and acquiring detection data of each gas concentration sensor; S35: When the detection values ​​of each gas concentration sensor return to zero, each three-way solenoid valve in the fast switching module is synchronously switched to the first state, the detection data of each gas concentration sensor is recorded, and the response curve of the gas concentration sensor under the current test cycle is drawn; S4: Switch each three-way solenoid valve in the fast switching module to the second state, so that the detection value of each gas concentration sensor is reset to zero, and then repeat steps S2-S3 until the preset maximum number of cycles is reached; S5: According to the response curves of the gas concentration sensors obtained in each test cycle, the synchronization of the gas concentration sensors is evaluated, and the synchronization deviation of the gas concentration sensors in the current batch is calculated.

2. The method for testing the synchronization of a gas concentration sensor according to claim 1, characterized in that: In step S35, the response time of each gas concentration sensor is The calculation formula is: ， In the above formula, t 1 indicates the moment when the reading of each gas concentration sensor starts to rise from 0 in each test cycle; t 2 indicates the moment when the reading of each gas concentration sensor rises to the maximum value; In step S5, the synchronization deviation of each gas concentration sensor in the current batch The calculation formula is as follows: ， In the above formula, Indicates i Synchronicity deviation of the wheel test cycle, Indicates i The maximum value of the response time of each gas concentration sensor in the round test cycle; Indicates i The minimum value of the response time of each gas concentration sensor in the round test cycle; n Indicates the preset maximum number of loops.

3. The method for testing the synchronization of a gas concentration sensor according to claim 1, characterized in that: A pressure reducer is also provided at the exhaust port of the high-pressure storage tank, and the pressure reducer is used to adjust the flow rate of the sample gas discharged from the high-pressure storage tank.

4. The method for testing the synchronization of a gas concentration sensor according to claim 3, characterized in that: The exhaust port of the high-pressure storage tank is connected to the gas inlet of the buffer tank through a three-way pipe, and the other port of the three-way pipe is connected to the atmosphere through a second balancing valve; The second balancing valve serves as a redundancy for the first balancing valve and is used to adjust the opening of the exhaust passage between the buffer tank and the atmosphere.

5. The method for testing the synchronization of a gas concentration sensor according to claim 1, characterized in that: It also includes a gas collecting device, which is connected to the exhaust port of the vacuum pump and the gas outlet of the buffer tank respectively and is used to collect the sample gas exhausted from the two.

6. The method for testing the synchronization of a gas concentration sensor according to claim 1, characterized in that: The air pressure sensor includes a meter head and a sensitive element, wherein the sensitive element is inserted into the inner cavity of the buffer tank; the meter head is located outside the buffer tank and is used to display the pressure data detected by the sensitive element; and / or The host computer also includes a display module, which is used to display the progress, data and results of the synchronization test tasks of each gas concentration sensor.

7. The method for testing the synchronization of a gas concentration sensor according to claim 1, characterized in that: Each three-way solenoid valve in the fast switching module synchronously switches the connection state between the air outlet end and one of the air inlet ends according to the instruction issued by the host computer.

8. The method for testing the synchronization of a gas concentration sensor according to claim 1, characterized in that: The air inlet of the vacuum pump is connected to a multi-port manifold block; each exhaust pipe is connected to each air hole on the manifold block; and / or The number of air holes of the manifold block corresponds one to one with the number of the sampling pipes and the air extraction pipes and the number of the three-way solenoid valves.

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