Sensor Performance Test Chamber

Abstract

Sensor performance test chamber, including a base, on which a box body is provided, a box cover is provided on the top of the box body, a panel located on the front side of the box body is provided on the base, a temperature and humidity sensor and a gas concentration sensor are provided inside the box body, a box body air inlet, a box body sampling port, a box body exhaust port and a sensor test interface are provided on the right side wall of the box body, a panel air inlet, a plurality of communication interfaces, a panel air outlet and a panel sampling port are provided on the panel, the panel air inlet is connected to the box body air inlet, the panel sampling port is connected to the box body sampling port, and the panel air outlet is connected to the box body exhaust port. The present invention realizes batch testing of the performance of gas sensors, improves the testing efficiency, can provide an experimental environment with uniform temperature, humidity and gas concentration, makes the batch testing of sensors more consistent, and has functions such as test environment monitoring and test signal output; it meets the requirements for testing the performance of sensors under harsh working conditions such as low-concentration, adsorbable, toxic and harmful, and corrosive gases.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor performance testing, and particularly relates to a test chamber for testing the performance changes of multiple sensors in an environment where the gas concentration, temperature, and humidity are adjustable. Background Art

[0002] The widespread application of gas sensors has driven the rapid development of the gas sensor industry. In particular, low-concentration gas sensors (such as PPM-level gas sensors), volatile gas or toxic and harmful gas sensors have developed more rapidly due to their special uses. However, the current backward gas sensor testing equipment has restricted the rapid development of the gas sensor industry.

[0003] The performance of gas sensors is greatly affected by temperature and gas humidity, and batch testing cannot be carried out. The testing process of the current testing tooling is relatively cumbersome, and the number of sensors tested each time is very small, 1-3 sensors. There will be certain differences in the environmental parameters (temperature, humidity, gas concentration) of the testing tooling when each sensor is tested, resulting in poor consistency of the measured sensor performance.

[0004] Currently, sensors are developing towards miniaturization and intelligence, and are being increasingly widely used. Realizing batch testing of sensors, improving the efficiency, accuracy, and consistency of sensor testing is of great significance to the development of the sensor industry. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides a closed test chamber that can perform batch testing of sensors, can test the performance of PPM-level volatile, adsorptive, corrosive, toxic and harmful gas sensors, and can evenly process environmental gas concentration, humidity, temperature, etc. during sensor testing.

[0006] To solve the above technical problems, the present invention adopts the following technical solution: A sensor performance test chamber, including a base, a box body is provided on the base, a box cover is provided on the top of the box body, a panel is provided on the base in front of the box body, a temperature and humidity sensor and a gas concentration sensor are provided inside the box body, a box body air inlet, a box body sampling port, a box body exhaust port, and a sensor test interface are provided on the right side wall of the box body, a panel air inlet, multiple communication interfaces, a panel air outlet, and a panel sampling port are provided on the panel, the panel air inlet is connected to the box body air inlet through a gas delivery pipe, the gas delivery pipe is arranged as a heating coil structure on the base at the rear side of the box body, the panel sampling port is connected to the box body sampling port through a sampling pipe, the panel air outlet is connected to the box body exhaust port through an exhaust pipe, the temperature and humidity sensor and the gas concentration sensor are respectively connected to one of the communication interfaces through data lines, and the sensor test interface and the other communication interfaces are connected through signal lines.

[0007] The front side wall of the box body is provided with an observation window made of tempered glass. The periphery of the observation window is sealed with the box body through a polytetrafluoroethylene gasket; an LED light strip for lighting is pasted on the outer side of the observation window; the LED light strip is connected to a communication interface through a wire, and a sensor placement platform is arranged at the bottom inside the box body.

[0008] A gas distribution multiplier connected to the air inlet of the box body is arranged on the right side inside the box body. The gas distribution multiplier includes a guide cylinder with its center line horizontally arranged in the left-right direction. A cylinder cover is buckled at the right end of the guide cylinder. An air permeable hole corresponding to and communicating with the guide cylinder is opened in the middle of the cylinder cover. An annular flow guide groove is axially opened on the right end face of the guide cylinder. The rear side of the guide cylinder is connected to the air inlet of the box body through an L-shaped connecting pipe. The front end of the L-shaped connecting pipe is connected to the annular flow guide groove. An outer sealing buckle ring for corresponding assembly with the outer circle of the right end face of the guide cylinder through a rabbet structure is arranged on the outer circle of the left end face of the cylinder cover. An inner buckle ring extending into the interior of the right port of the cylinder cover is arranged on the inner circle of the left end face of the cylinder cover. A circular jet gap is formed between the inner buckle ring and the inner circle of the right port of the guide cylinder. An annular channel for communicating the jet gap and the annular flow guide groove is arranged on the left end face of the cylinder cover.

[0009] The cylinder cover, the outer sealing buckle ring and the inner buckle ring are integrally made with the guide cylinder. The outer circle of the left side of the guide cylinder is a first conical surface that is thinner on the left and thicker on the right. The guide cylinder and the outer sealing buckle ring are connected by countersunk head screws;

[0010] The inner circle of the left side part of the guide cylinder is a second conical surface that is thicker on the left and thinner on the right. The part of the inner circle of the guide cylinder from the minimum diameter of the second conical surface to the jet gap is a third conical surface that is thinner on the left and thicker on the right.

[0011] A stop valve is arranged on the sampling pipe, and an adjustable flowmeter is arranged on the exhaust pipe.

[0012] An internal threaded hole communicating with the annular flow guide groove is radially opened on the rear side of the guide cylinder. The front end of the L-shaped connecting pipe extends into and is threadedly connected to the internal threaded hole.

[0013] The rear side of the box cover is hinged to the box body through a hinge. A handle is arranged on the front side of the box body. The box cover and the box body are tightly connected through C-shaped clamps on both the left and right sides. A fluororubber gasket is arranged between the lower side edge of the box cover and the upper side edge of the box body. Under the action of the C-shaped clamps, the box cover tightly presses the box body through the fluororubber gasket to seal the internal cavity of the box body.

[0014] An insulating cotton is arranged between the bottom of the box body and the base. An aluminum foil layer is arranged on the side surface of the insulating cotton adjacent to the base.

[0015] A left flow dividing cone cylinder with a pointed right end is arranged on the left inner wall of the box body. A right flow dividing cone cylinder with a pointed left end is arranged on the right inner wall of the box body. The center lines of the left flow dividing cone cylinder, the right flow dividing cone cylinder and the guide cylinder coincide.

[0016] An annular gas outlet pipe is provided on the outer circle of the draft tube along the center line. The gas outlet pipe and the draft tube are fixed on the right side wall of the box body through connecting brackets. A number of gas outlet holes are opened on the left side of the gas outlet pipe, and the rear side of the gas outlet pipe is connected to the exhaust port of the box body through a gas guide pipe.

[0017] With the above technical solution, the aluminum foil layer on the side of the heat insulation cotton has the function of heat insulation and heat radiation prevention; there is a heating coil structure at the rear of the base. The function is that when the entire test box is placed in a high and low temperature test chamber, the heating coil structure is heated to heat the gas entering the box body. The length of the heating coil structure can be adjusted according to the intake air volume, so that the entering gas is completely heated to the temperature in the high and low temperature test chamber; the front panel of the base integrates the panels of interfaces such as air intake, sampling, exhaust, signal, and control.

[0018] The box body and the box cover are all made of 316 stainless steel. The box cover and the box body are sealed through fluororubber gaskets. The two are connected by hinges at the rear and are clamped by C-shaped clamps during experiments to achieve sealing; the inside of the box body is highly polished to reach the mirror standard, which can maximize the anti-adsorption and anti-corrosion effects;

[0019] There is a large-area observation window at the front of the box body, which is convenient for observing the state of the sensor during the test. The opening and closing of the LED light strip can be controlled through the communication interface. The sensor placement platform is used to place the sensor to be tested;

[0020] On the right side inside the box body, according to the intake air volume and the box body size, a gas distribution multiplier is provided to evenly eject the intake air and draw the air flow at the right port of the cylinder cover to the left, which is the power source for the gas to circulate inside the box body; an annular gas outlet pipe is arranged outside the draft tube, and a number of gas outlet holes (or a metal etching net with small apertures) are evenly arranged on the left surface of the gas outlet pipe, which can evenly exhaust the gas inside the box body to the outside; at the center positions of the right side surface and the left side surface of the box body, there is a conical left flow dividing cone tube and a right flow dividing cone tube respectively, which are used to evenly reverse the gas inside the box body to generate a uniform flow field; the cooperation among the gas distribution multiplier, the left flow dividing cone tube, the right flow dividing cone tube and the annular gas outlet pipe can make the gas distribution inside the box body uniform, so as to make the gas concentration and humidity distribution inside the box body uniform.

[0021] At the same time, a temperature and humidity sensor, a gas concentration sensor, a gas sampling port, etc. are also integrated on the right side wall inside the box body to monitor the internal environment parameters of the box body and facilitate the feedback adjustment of external gas generating devices, high and low temperature test chambers and other equipment.

[0022] The right side wall inside the box body also has an integrated multi-channel wire harness interface for the sensor to output electrical signals, which is used to supply power to the sensor performance test and output electrical signals.

[0023] When the present invention is in operation, first open the box cover, place the batch of sensors to be tested on the sensor placement platform at the bottom of the lower box body, connect the wires of each sensor, and connect them to the integrated multi-channel wire harness interface inside the box body. Close the box cover and clamp it with a C-clamp. Place the entire test box into the high and low temperature test chamber, and then connect the intake pipe (connected to the panel intake port), the sampling pipe (connected to the panel sampling port), the exhaust pipe (connected to the gas collection tank), and the wire harness interface at the panel on the front side of the base. Close the door of the high and low temperature test chamber, adjust the gas distribution equipment, and then the experiment can be carried out. The sensor performance test box can output the electrical signals of numerous sensors to the signal processing system, thereby testing the performance of the batch of sensors.

[0024] The principle of this box body design is: to create an environment with uniform temperature, humidity, and gas concentration for the performance test of a batch of sensors. A heating coil structure is set up so that the gas can reach the temperature inside the high and low temperature test chamber before entering the box body. Since the entire device is placed inside the high and low temperature test chamber, the temperature of the box body is the same as the temperature of the finally entering gas, which can make the temperature uniform. At the same time, the design of the base and the heat insulation cotton can isolate the box body from the cool air after the heating coil structure, avoiding affecting the temperature. The gas outlet volume is adjusted through an adjustable flowmeter to adjust the gas concentration inside the box. When sampling, the stop valve can be opened and sampling can be carried out through the panel sampling port.

[0025] In summary, the beneficial effects of the present invention are:

[0026] 1. Realize the batch testing of the performance of gas sensors and improve the testing efficiency;

[0027] 2. Can provide an experimental environment with uniform temperature, humidity, and gas concentration, making the batch testing of sensors more consistent;

[0028] 3. Has functions such as test environment monitoring and test signal output, with complete functions and convenient use;

[0029] 4. Meet the requirements for the performance testing of sensors under harsh working conditions such as low concentration, adsorbable, toxic and harmful, and corrosive gases. Brief Description of the Drawings

[0030] Figure 1 is the three-dimensional structure schematic diagram of the present invention;

[0031] Figure 2 is the top view of the present invention after removing the lower box cover;

[0032] Figure 3 is the left sectional view of the present invention;

[0033] Figure 4 is the pipeline and wiring diagram of the sensor performance test box in the present invention;

[0034] Figure 5 It is a three-dimensional structural schematic diagram of the gas distribution multiplier in the present invention;

[0035] Figure 6 It is an axial sectional structural schematic diagram of the gas distribution multiplier in the present invention;

[0036] Figure 7 is Figure 6 the enlarged view of part A in Specific embodiments

[0037] As Figures 1-7 shown, the sensor performance test box of the present invention includes a base 1, a box body 2 is provided on the base 1, a box cover 3 is provided on the top of the box body 2, a panel 4 is provided on the base 1 at the front side of the box body 2, a temperature and humidity sensor 5 and a gas concentration sensor 6 are provided in the box body 2, a box body air inlet 7, a box body sampling port 8, a box body exhaust port 9 and a sensor test interface 10 are provided on the right side wall of the box body 2, a panel air inlet 11, three communication interfaces 12, a panel air outlet 13 and a panel sampling port 14 are provided on the panel 4, the panel air inlet 11 is connected to the box body air inlet 7 through a gas delivery pipe 16, the gas delivery pipe 16 is arranged as a heating coil structure 15 on the base 1 at the rear side of the box body 2, the panel sampling port 14 is connected to the box body sampling port 8 through a sampling pipe 17, the panel air outlet 13 is connected to the box body exhaust port 9 through an exhaust pipe 18, the temperature and humidity sensor 5 and the gas concentration sensor 6 are respectively connected to one of the communication interfaces 12 through data lines, and the sensor test interface 10 is connected to the other communication interfaces 12 through signal lines.

[0038] An observation window 19 is provided on the front side wall of the box body 2, the observation window 19 is made of tempered glass, and the periphery of the observation window 19 is sealed with the box body 2 through a polytetrafluoroethylene gasket; an LED light strip 20 for lighting is pasted on the outside of the observation window 19; the LED light strip 20 is connected to one of the communication interfaces 12 through a wire, and a sensor placement platform 21 is provided at the bottom inside the box body 2.

[0039] On the right side inside the box body 2, there is a gas distribution multiplier 22 connected to the air inlet 7 of the box body. The gas distribution multiplier 22 includes a guide cylinder 23 with its center line horizontally arranged in the left-right direction. A cover 24 is buckled at the right end of the guide cylinder 23. A breathable hole corresponding to and communicating with the guide cylinder 23 is opened in the middle of the cover 24. An annular guide groove 25 is axially opened on the right end face of the guide cylinder 23. The rear side of the guide cylinder 23 is connected to the air inlet 7 of the box body through an L-shaped connecting pipe 26. The front end of the L-shaped connecting pipe 26 is connected to the annular guide groove 25. An outer sealing buckling ring 27 is arranged on the outer circle of the left end face of the cover 24 and is correspondingly assembled with the outer circle of the right end face of the guide cylinder 23 through a rabbet structure. An inner buckling ring 28 extending into the interior of the right port of the cover 24 is arranged on the inner circle of the left end face of the cover 24. A circular jet gap 29 is formed between the inner buckling ring 28 and the inner circle of the right port of the guide cylinder 23. An annular channel 30 for communicating the jet gap 29 and the annular guide groove 25 is arranged on the left end face of the cover 24.

[0040] The cover 24, the outer sealing buckling ring 27 and the inner buckling ring 28 are integrally made with the guide cylinder 23. The outer circle of the left side of the guide cylinder 23 is a first conical surface 31 that is thinner on the left and thicker on the right. The guide cylinder 23 and the outer sealing buckling ring 27 are connected by countersunk head screws;

[0041] The inner circle of the left side part of the guide cylinder 23 is a second conical surface 32 that is thicker on the left and thinner on the right. The part of the inner circle of the guide cylinder 23 between the minimum diameter of the second conical surface 32 and the jet gap 29 is a third conical surface 33 that is thinner on the left and thicker on the right.

[0042] A stop valve 34 is arranged on the sampling pipe 17, and an adjustable flowmeter 35 is arranged on the exhaust pipe 18.

[0043] An internal threaded hole communicating with the annular guide groove 25 is radially opened on the rear side of the guide cylinder 23. The front end of the L-shaped connecting pipe 26 extends into and is threadedly connected to the internal threaded hole.

[0044] The rear side of the box cover 3 is hinged to the box body 2 through a hinge 36. A handle 37 is arranged on the front side of the box body 2. The box cover 3 and the box body 2 are tightly connected through C-shaped clamps 38 on both the left and right sides. A fluororubber gasket 39 is arranged between the lower side edge of the box cover 3 and the upper side edge of the box body 2. Under the action of the C-shaped clamps 38, the box cover 3 tightly presses the box body 2 through the fluororubber gasket 39 to seal the internal cavity of the box body 2.

[0045] An insulating cotton 40 is arranged between the bottom of the box body 2 and the base 1. An aluminum foil layer is arranged on the side surface of the insulating cotton 40 adjacent to the base 1.

[0046] A left diversion cone cylinder 41 with a pointed right end is arranged on the left inner wall of the box body 2, and a right diversion cone cylinder 42 with a pointed left end is arranged on the right inner wall of the box body 2. The center lines of the left diversion cone cylinder 41, the right diversion cone cylinder 42 and the guide cylinder 23 coincide.

[0047] An annular air outlet pipe 43 is provided on the outer circle of the draft tube 23 along the center line. The air outlet pipe 43 and the draft tube 23 are fixed on the right side wall of the box body 2 through a connecting bracket 44. A number of air outlet holes are provided on the left side of the air outlet pipe 43, and the rear side of the air outlet pipe 43 is connected to the exhaust port 9 of the box body through a guide pipe.

[0048] The aluminum foil layer on the side of the heat insulation cotton 40 has the function of heat insulation and heat radiation prevention; there is a heating coil structure 15 at the rear of the base 1. The function is that when the entire test box is placed in a high and low temperature test box, the heating coil structure 15 is heated to heat the gas entering the box body 2. The length of the heating coil structure 15 can be adjusted according to the intake air volume, so that the entering gas is completely heated to the temperature in the high and low temperature test box; the front panel 4 of the base 1 integrates the panel 4 with interfaces such as air intake, sampling, exhaust, signal, and control.

[0049] The box body 2 and the box cover 3 are all made of 316 stainless steel. The box cover 3 and the box body 2 are sealed through a fluororubber gasket 39. The two are connected through a hinge 36 at the rear and are clamped by a C-type clamp 38 during the experiment to achieve sealing; the inside of the box body 2 is highly polished to reach the mirror standard, which can maximize the anti-adsorption and anti-corrosion effects;

[0050] There is a large-area observation window 19 at the front of the box body 2, which is convenient for observing the state of the sensor during the test. The on and off of the LED light strip 20 can be controlled through the communication interface 12. The sensor placement platform 21 is used to place the sensor to be tested;

[0051] On the right side inside the box body 2, according to the size of the intake air volume and the size of the box body 2, a gas distribution multiplier 22 is provided, which is used to evenly spray the intake air and draw the air flow at the right port of the cylinder cover 24 to the left side, which is the power source for the gas in the box body 2 to generate circulation; an annular air outlet pipe 43 is arranged outside the draft tube 23, and a number of air outlet holes (or a metal etching net with small apertures) are evenly arranged on the left surface of the air outlet pipe 43, which can evenly exhaust the gas inside the box body 2 to the outside; there is a conical left flow dividing cone tube 41 and a right flow dividing cone tube 42 at the center of the right side and the left side of the box body 2 respectively, which are used to evenly reverse the gas inside the box body 2 to generate a uniform flow field; the cooperation among the gas distribution multiplier 22, the left flow dividing cone tube 41, the right flow dividing cone tube 42 and the annular air outlet pipe 43 can make the gas distribution inside the box body 2 uniform, so that the gas concentration and humidity distribution inside the box body 2 are uniform.

[0052] The gas distribution multiplier 22, based on the fluid mechanics principle - the Coanda effect, uses only a small amount of compressed gas as the power source. The compressed gas sequentially passes through the L-shaped connecting pipe 26, the annular diversion groove 25, and the annular channel 30, and finally is ejected backward along the third conical surface 33 through the annular jet slit 29, and then is ejected from the second conical surface 32 out of the diversion cylinder 23, driving the gas flow inside the diversion cylinder 23 and around the right side of the cylinder cover 24 to form a primary air flow ejected to the left. This primary air flow adheres to the inner circular surface of the diversion cylinder 23, so a low-pressure area is generated in the center of the cavity of the diversion cylinder 23, and thus a large amount of surrounding air is sucked in. After the primary air flow and the surrounding air flow converge, a high-speed and high-capacity air flow is formed, and the flow rate is several times that of the gas consumption. The structure is simple and the cost is low. Here, other equipment or materials in the box body 2 that are prone to adsorbing gas can be reduced, and the purpose of making the gas in the box body 2 mix evenly can also be achieved. At the same time, when performing micro gas experiments on the sensor, the influence of gas adsorption on the gas concentration in the closed test box can be reduced. Figure 6 The arrows shown indicate the air flow direction.

[0053] According to the flow rate of the panel air inlet 11 and the size of the box body, the annular size of the gas distribution multiplier 22, and the lengths and tapers of the second conical surface 32 and the third conical surface 33 of the diversion cylinder 23 are reasonably designed. By using the left diversion cone cylinder 41, the right diversion cone cylinder 42, and the circular annular air outlet pipe 43 on the box body 2, a uniform and stable flow field can be formed in the box body 2, so that the gas concentration, humidity, and temperature distributions in the gas entering the box body 2 are uniform. The left diversion cone cylinder 41 serves to diffuse the air flow from left to right in the up, down, front, and back directions and then fold it back to the right, and the right diversion cone cylinder 42 serves to divert the air flow folded back from right to left to the center and into the right port of the cylinder cover 24.

[0054] At the same time, a temperature and humidity sensor 5, a gas concentration sensor 6, a gas sampling port, etc. are also integrated on the right side wall inside the box body 2 to monitor the internal environmental parameters of the box body 2, facilitating feedback adjustment of external gas generating devices, high and low temperature test chambers, and other equipment.

[0055] The right side wall inside the box body 2 also has an integrated multi-channel wire harness interface for the sensor to output electrical signals, which is used to supply power for the sensor performance test and output electrical signals.

[0056] When the present invention is in operation, first open the box cover 3, place the batch of sensors to be tested on the sensor placement platform 21 at the bottom inside the lower box body 2, connect the wires of each sensor, and connect them to the integrated multi-channel wire harness interface inside the box body 2. Close the box cover 3 and clamp it with the C-shaped clamp 38. Place the entire test box into the high and low temperature test chamber, and then connect the intake pipeline (connected to the panel intake port 11), the 17 sampling pipelines (connected to the panel sampling port 14), the 43 exhaust pipelines (connected to the gas collection tank), and the wire harness interface, etc. at the panel 4 on the front side of the base 1. Close the door of the high and low temperature test chamber, adjust the gas distribution equipment, and then the experiment can be carried out. The sensor performance test box can output the electrical signals of numerous sensors to the signal processing system, thereby testing the performance of the batch of sensors.

[0057] The principle of the design of this box body 2 is: to create an environment with uniform temperature, humidity, and gas concentration for the performance test of a batch of sensors. The heating coil structure 15 is set up so that the gas can reach the temperature inside the high and low temperature test chamber before entering the box body 2. Since the entire device is placed inside the high and low temperature test chamber, the temperature of the box body 2 is the same as the temperature of the finally entering gas, which can make the temperature uniform. At the same time, the design of the base 1 and the heat insulation cotton 40 can isolate the box body 2 from the cool air after the heating coil structure 15, avoiding affecting the temperature. The gas output is adjusted by the adjustable flowmeter 35 to adjust the gas concentration inside the box body 2. When sampling, the stop valve 34 can be opened to sample through the panel sampling port 14.

[0058] This embodiment does not impose any formal restrictions on the shape, material, structure, etc. of the present invention. Any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention all belong to the protection scope of the technical solution of the present invention.

Claims

1. Sensor performance test box, characterized in that: It includes a base, on which there is a box body. There is a box cover on the top of the box body. There is a panel on the base at the front side of the box body. Inside the box body, there are a temperature and humidity sensor and a gas concentration sensor. On the right side wall of the box body, there are a box body air inlet, a box body sampling port, a box body exhaust port and an integrated multi-channel wire harness interface. On the panel, there are a panel air inlet, multiple communication interfaces, a panel air outlet and a panel sampling port. The panel air inlet is connected to the box body air inlet through a gas delivery pipe. The gas delivery pipe is arranged as a heating coil structure on the base at the rear side of the box body. The panel sampling port is connected to the box body sampling port through a sampling pipe. The panel air outlet is connected to the box body exhaust port through an exhaust pipe. The temperature and humidity sensor and the gas concentration sensor are respectively connected to one of the communication interfaces through data lines. The integrated multi-channel wire harness interface and the other communication interfaces are connected through signal lines; Inside the box body on the right side, there is a gas distribution multiplier connected to the box body air inlet. The gas distribution multiplier includes a diversion cylinder with its center line horizontally arranged in the left-right direction. A cover is buckled at the right end of the diversion cylinder. There is a breathable hole corresponding to and communicating with the diversion cylinder in the middle of the cover. An annular diversion groove is axially opened on the right end face of the diversion cylinder. The rear side of the diversion cylinder is connected to the box body air inlet through an L-shaped connecting pipe. The front end of the L-shaped connecting pipe is connected to the annular diversion groove. An outer sealing buckling ring is arranged on the outer circle of the left end face of the cover and is correspondingly assembled with the outer circle of the right end face of the diversion cylinder through a rabbet structure. An inner buckling ring extending into the interior of the right port of the cover is arranged on the inner circle of the left end face of the cover. A circular jet slit is formed between the inner buckling ring and the inner circle of the right port of the diversion cylinder. An annular channel for connecting the jet slit and the annular diversion groove is arranged on the left end face of the cover; The cover, the outer sealing buckling ring, the inner buckling ring and the diversion cylinder are integrally made. The outer circle of the left side part of the diversion cylinder is a first conical surface that is thinner on the left and thicker on the right. The diversion cylinder and the outer sealing buckling ring are connected by countersunk head screws; The inner circle of the left side part of the diversion cylinder is a second conical surface that is thicker on the left and thinner on the right. The part of the inner circle of the diversion cylinder between the minimum diameter of the second conical surface and the jet slit is a third conical surface that is thinner on the left and thicker on the right; On the left inner wall of the box body, there is a left diversion cone cylinder with a pointed right end. On the right inner wall of the box body, there is a right diversion cone cylinder with a pointed left end. The center lines of the left diversion cone cylinder, the right diversion cone cylinder and the diversion cylinder coincide.

2. The sensor performance test box according to claim 1, characterized in that: On the front side wall of the box body, there is an observation window made of tempered glass. The periphery of the observation window is sealed with the box body through a polytetrafluoroethylene gasket; An LED light strip for lighting is pasted on the outside of the observation window; The LED light strip is connected to a communication interface through a wire. There is a sensor placement platform at the bottom inside the box body.

3. The sensor performance test chamber according to claim 1 or 2, characterized in that: A stop valve is arranged on the sampling pipe, and an adjustable flowmeter is arranged on the exhaust pipe.

4. The sensor performance test box according to claim 1 or 2, characterized in that: An internal threaded hole communicating with the annular diversion groove is axially opened on the rear side of the diversion cylinder. The front end of the L-shaped connecting pipe extends into and is threadedly connected to the internal threaded hole.

5. The sensor performance test chamber according to claim 1 or 2, characterized in that: The rear side of the box cover is hinged to the box body through a hinge. There is a handle on the front side of the box body. The box cover and the box body are tightly connected through C-shaped clamps on both the left and right sides. There is a fluororubber gasket between the lower side edge of the box cover and the upper side edge of the box body. Under the action of the C-shaped clamps, the box cover tightly presses the box body through the fluororubber gasket to seal the internal cavity of the box body.

6. The sensor performance test box according to claim 1 or 2, characterized in that: There is a heat insulation cotton between the bottom of the box body and the base. There is an aluminum foil layer on the side of the heat insulation cotton adjacent to the base.

7. The sensor performance test box according to claim 1, characterized in that: An annular air outlet pipe is provided along the center line of the outer circle of the draft tube. The air outlet pipe and the draft tube are fixed to the right side wall of the box body through a connecting bracket. A number of air outlet holes are opened on the left side of the air outlet pipe, and the rear side of the air outlet pipe is connected to the exhaust port of the box body through an air duct.

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