CN114720381A - Trace ozone concentration measuring device - Google Patents

Abstract

The invention belongs to the field of measuring environmental ozone concentration by a chemiluminescence method, and particularly relates to a trace ozone concentration measuring device. The shape of the detachable thermostatic chamber is a cuboid box, the long axis of the ellipsoid light-emitting chamber is along the long edge direction of the cuboid box, the long edge of the cuboid box is larger than 2 times of the long axis of the ellipsoid light-emitting chamber, the two short edges of the cuboid box are the same in length, and the short edge of the cuboid box is larger than 2 times of the short axis of the ellipsoid light-emitting chamber; the temperature inside the detachable thermostatic chamber is in a temperature section suitable for the fluorescence generation of excited NO 2; the invention has the advantages that the detachable ellipsoid light-emitting chamber is arranged in the thermostatic chamber, the optimal temperature of chemiluminescence is kept by utilizing the optical characteristic of total internal reflection of the ellipsoid and the constant temperature characteristic of the thermostatic chamber, the ozone detection limit is improved, and the utilization rate of fluorescence light exceeds 90 percent.

Description

A device for measuring trace ozone concentration

technical field

The invention belongs to the field of environmental ozone concentration measurement by chemiluminescence method, and particularly relates to a trace ozone concentration measurement device.

Background technique

The daily ozone pollution refers to photochemical smog. The essence of photochemical smog is that primary pollutants such as nitrogen oxides and hydrocarbons discharged into the atmosphere by pollution sources such as automobiles and factories undergo photochemical reactions under the irradiation of solar ultraviolet rays to generate secondary pollutants such as ozone. Ozone has a strong irritant, mainly stimulates and damages the deep respiratory tract, and can damage the central nervous system, and has a mild irritating effect on the eyes. Usually, the measurement of ozone concentration requires imported expensive ultraviolet measuring instruments. The measurement of trace ozone concentration by chemiluminescence is a research achievement in recent years. The principle of chemiluminescence measurement of trace ozone: the NO standard gas and the gas containing O3 are introduced into the reaction chamber in opposite directions, and the O3 and NO react to generate excited NO2* molecules, but the NO2* molecules cannot exist stably, and it will rapidly decay to The NO2 in the ground state, the time is less than 1 nanosecond, radiates the fluorescence with the center wavelength of 1200nm, the light emission direction is random, and its spectral range is 600-3000nm. In the case of excessive NO in the standard gas, it can be approximated that O3 is completely depleted, and the measured fluorescence intensity is proportional to the concentration of O3, so that trace ozone in the environment can be accurately measured. The fluorescence signal is weak, the light decays quickly, and it can only travel 100 mm, making it difficult to observe. Optical characteristics of ellipsoid chemiluminescence reaction chamber: There are two focal points inside the ellipsoid. The light emitted from one of the focal points will be concentrated on the other focal point after being reflected by the inner cavity surface of the ellipsoid. The ellipsoid luminescence chamber is very good. chemiluminescence reaction chamber. The idea is as follows: 1. Set the long axis of the ellipsoid light-emitting chamber as the x-axis, and cut it from the vertical plane of the origin of the long axis of the ellipsoid light-emitting chamber to form the left and right ellipsoid light-emitting chambers, which is convenient for installing internal devices. Distribute six flange ears at equal distances, and set threaded through holes in the middle of the flange ears. Use bolts to close the left and right ellipsoid light-emitting chambers to form a complete shading and sealed ellipsoid light-emitting chamber, which meets the reflection conditions in the cavity; 2. The left half The ellipsoid light-emitting room and the right semi-ellipsoid light-emitting room are made of cast aluminum parts. Since ozone gas is a strong corrosive medium, the polished aluminum film inside the ellipsoid light-emitting room can reflect light and resist the strong corrosion of ozone gas. 3. Add quartz glass lenses between the left and right ellipsoid light-emitting chambers. After closing the left and right ellipsoid light-emitting chambers through the six flange ears, threaded through holes and bolts of the left and right ellipsoid light-emitting chambers, the quartz glass lens closes the ellipsoid light-emitting chambers. Divided into two halves, the left semi-ellipsoid light-emitting chamber is a sealed semi-ellipsoid reaction gas chamber, and the right semi-ellipsoid light-emitting chamber is a closed optical receiving chamber; while the quartz glass lens in the middle of the ellipsoid is completely transparent to chemiluminescence, still satisfying The law of optical reflection in ellipsoid cavity. 4. Set the environmental sample gas (including ozone) input pipeline, the standard gas input pipeline, the ambient sample gas (including ozone) input pipeline and the standard gas input pipeline NO The gas intersection point, that is, the chemiluminescence point, is at the left focus of the left semi-ellipsoid luminescence chamber, forming a chemiluminescence chamber; an exhaust pipe is set on the ellipsoid luminescence chamber corresponding to the long axis of the left ellipsoid luminescence chamber to discharge the reacted waste gas in real time; 5 The chemiluminescence point is at the left focus of the ellipsoid, any light at the left focus is reflected directly or through a point inside the ellipsoid light-emitting chamber, and converges at the right focus of the ellipsoid, forming a luminous reflection optical path; all luminescence in the ellipsoid The reflected optical path is always equal to 2c, all of which converge at the right focus of the ellipsoid; 6. Install a photomultiplier tube on the right focal plane of the ellipsoid light-emitting chamber, and the light absorption window of the photomultiplier tube is at the right focus of the ellipsoid. Fluorescence in all directions. 7. In order to eliminate the influence of ambient temperature on chemiluminescence, the whole ellipsoid is set in a constant temperature room. The heat capacity of the ellipsoid itself is large, which can offset the temperature drop caused by the input gas; the temperature inside the ellipsoid is controlled by the MCU microprocessor to be constant, and the temperature in the reaction chamber is in the optimal range of chemiluminescence. 8. The MCU microprocessor regularly starts the sampling gas pump, the sample gas flow, the standard gas pressure reducing switch and the standard gas flow, and the flow ratio is 1/10 to ensure that the ozone completely converts the excited state NO2* to emit light. 9. The MCU microprocessor receives the photomultiplier tube power signal, converts it into an ozone concentration signal, displays and uploads it to the upper computer.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a measuring device for measuring ozone gas concentration by chemical fluorescence method.

The technical solution of the present invention: a trace ozone concentration measuring device, characterized in that the detachable ellipsoid light-emitting chamber of the ozone concentration measuring device is installed inside the detachable constant temperature chamber (10);

As shown in Figure 1, the detachable constant temperature chamber (10) is in the shape of a long cubic box (101), and the long axis of the ellipsoid light-emitting chamber is along the long side direction of the long cubic box (101). The long side of the ellipsoid light-emitting chamber is longer than twice the long axis, the length of the two short sides of the long cubic box (101) is the same, and the length of the short side of the long cubic box (101) is greater than twice the short axis of the ellipsoid light-emitting chamber; The four corners of the cube box (101) are provided with fixing screw seats (104), the upper and lower covers of the long cube box (101) are movable covers, and the upper and lower covers and gaskets are fixed with screws at the four corners; the long cube box (101) ) is also provided with a heating rod (102) and a temperature sensor (103) inside, and the heating rod (102) and the temperature sensor (103) are electrically connected to the MCU microprocessor (11), which controls the detachable constant temperature chamber ( 10) Internal constant temperature; preferably, the internal temperature of the detachable constant temperature chamber (10) is in the temperature range suitable for excited state NO2* fluorescence generation; the preferred ellipsoid 2 times the long axis is less than or equal to the fluorescence propagation distance of 100 mm;

As shown in Figure 2, the detachable ellipsoid light-emitting chamber includes a left ellipsoid shell (1), six flanges under the left and right ellipsoid shells (4), a quartz glass lens (5), a right ellipsoid The spherical shell (7), the six flange ears (8) outside the left and right ellipsoid shells; the left ellipsoid shell (1) and the right ellipsoid shell (7) are cast aluminum ellipsoid shells, cast aluminum Polish the inside of the spherical shell; as shown in Figure 2, add a quartz glass lens (5) between the left ellipsoid shell (1) and the right ellipsoid shell (7), the left ellipsoid shell (1) and the right The ellipsoid shell (7) is mechanically connected by threaded through-hole bolts under the six outer flange ears (4) and the six flange ears (7), the left ellipsoid shell (1) and the right ellipsoid shell (7) Close up to form a detachable ellipsoid light-emitting chamber; further, as shown in Figure 2, the left ellipsoid shell (1) and the quartz glass lens (5) form a closed light-emitting reaction chamber; On the cross-section of the plane x=-c, starting from the horizontal line passing through the focal point on the cross-section, set up the opposite sealable openings in the clockwise direction, and set up the standard gas input pipeline (3), the environmental sample gas input pipeline (9), and the environmental sample gas input pipeline (9). The sample gas input pipe (9) and the standard gas input pipe (3) are on a diameter that passes through the focal point; a sealable hole is arranged on the long axis of the left ellipsoid light-emitting chamber, and an exhaust pipe (2) is installed at the sealable hole;

Further, the ambient sample gas input pipeline (9) and the standard gas input pipeline (3) arranged opposite to the focal plane x=-f of the left ellipsoid shell (1) are arranged opposite to each other around the focal point of the ellipsoid shell, and the two gases The intersection point of ozone and NO is at the focal point of the left ellipsoid shell, NO gas wraps the ozone gas, the exhaust pipe is on the long axis of the left ellipsoid shell, and the two gases meet and mix to excite chemiluminescence at the focus of the left ellipsoid shell;

The quartz glass lens (5) and the right ellipsoid shell (7) form a closed photoelectric conversion chamber, and the right ellipsoid shell (7) is drilled along the focal plane x=f of the ellipsoid light-emitting chamber, and a photomultiplier tube is installed. (6), the optical window of the photomultiplier tube (6) is at the focus of the right ellipsoid shell; the chemiluminescence at the focus of the left ellipsoid shell (1), directly or through the internal reflection of the ellipsoid shell, passes through the left ellipsoid shell The quartz glass lens (5) between the spherical shell (1) and the right ellipsoid shell (7) is optically connected to the photomultiplier tube (6) optical window of the focus of the right ellipsoid shell (7);

Further, the exhaust pipe (2), the standard gas pipe (3) and the ambient sample gas input pipe (9) pass through the left wall of the detachable constant temperature chamber (10), wherein the ambient sample gas input pipe (9) is connected to the sample gas flow The inlet end of the meter (91), the outlet end of the sample gas flowmeter (91) is connected to the outlet end of the peristaltic sampling pump (92), and the inlet end of the peristaltic sampling pump (92) is connected to the sampling port (93) with a particle filter; The gas input pipeline (3) is connected to the inlet end of the standard gas flowmeter (31), the outlet end of the standard gas flowmeter (31) is connected to the standard gas pressure reducing valve (32), and the standard gas pressure reducing valve (32) is connected to the standard gas source (33); The exhaust pipe (2) is connected to the one-way valve (22), the one-way valve (22) is connected to the exhaust gas exhaust port (20), and the one-way valve (22) only allows one-way ventilation;

As shown in Figure 3, the standard gas pressure reducing valve (32), the peristaltic sampling pump (92), the heating rod (102), the temperature sensor (103) and the photomultiplier tube (6) are electrically connected to the MCU microprocessor (11), The MCU microprocessor (11) is electrically connected to the display screen (12); the MCU microprocessor (11) receives the electric quantity signal of the photomultiplier tube, converts it into an ozone concentration signal, displays the ozone concentration and uploads it to the upper computer.

Brief description of the working principle of a trace ozone concentration measurement device of the present invention: Optical characteristics inside the ellipsoid: the light emitted from one of the left and right focal points inside the ellipsoid, after being reflected by the inner surface of the ellipsoid, will converge on the another focus. From the optical characteristics of the ellipsoid, it is inferred that the ellipsoid luminescence chamber is a good chemiluminescence reaction chamber. The detachable ellipsoid light-emitting reaction chamber is cut with a vertical plane from the long axis x=0, which are the left half-cast aluminum ellipsoid spherical shell and the right half-cast aluminum ellipsoid spherical shell; A gasket is added between the sections of the light-emitting chamber, the left and right semi-cast aluminum ellipsoid spherical shells are mechanically connected by six flange ears and threaded through-hole bolts on the outer edge, and the left and right ellipsoid light-emitting chambers are closed to form an internal airtightness The left half ellipsoid light-emitting reaction chamber is shaded; the interior of the left and right ellipsoid light-emitting chambers is polished to facilitate fluorescence reflection; in order to eliminate the influence of ambient temperature on chemiluminescence, the ellipsoid light-emitting chamber is inside the constant temperature chamber, and is controlled by the MCU microprocessor (11) Control the temperature to a constant 50 degrees.

The MCU microprocessor (11) controls the sample gas pump, the sample gas flowmeter, the standard gas pressure reducing switch and the standard gas flowmeter to ensure that the ozone completely converts the excited state NO to emit light; at a suitable temperature of 50 degrees Celsius, the interior of the ellipsoid spherical reaction chamber In the left focal plane, the input pipeline of ambient sample gas (containing ozone) is thin, and the input pipeline of standard gas is thick. The intersection point of the two gases is near the left focus of the ellipsoid, and NO wraps O3 gas; NO reacts with O3 to generate excited state NO2* Molecules, and NO2* molecules cannot exist stably, it will rapidly decay to ground state NO2, the time is less than 1 nanosecond, and radiate fluorescence with a central wavelength of 1200nm, its spectral range is 600-3000nm, and the luminous point is near the focus; Quartz glass lens, can pass all the fluorescence of 600-3000nm. The exhaust pipe is perpendicular to the input pipe of ambient sample gas (containing ozone) and the input pipe of standard gas, and the exhaust pipe points to the focus along the long axis direction. Exhaust, the gas light-emitting band is at the focus of the left ellipsoid; by adjusting the diameter of the ambient sample gas (containing ozone) input pipe and the standard gas input pipe, the distance between the pipes, and the flow rate, all the O3 gas can be guaranteed. Luminescence reaction; the mixing process of gas is basically in the focal plane of the left-cast aluminum ellipsoid, and the light-emitting surface is in the focal plane of the left-cast aluminum ellipsoid; The polished aluminum film reflects light and focuses on another focal point of the ellipsoid. All the light is reflected inside the ellipsoid shell and reaches the right focus of the ellipsoid through the quartz glass lens in between; the photomultiplier tube installed at the right focus of the ellipsoid receives all the light. The light from the left focal plane of the ellipsoid is reflected by the ellipsoid, passes through the quartz glass lens, and the light is connected to the photomultiplier tube; the photomultiplier tube converts the fluorescence intensity into a voltage signal, the light intensity is proportional to the voltage, and the voltage signal is ozone concentration signal. The MCU microprocessor (11) receives the power signal of the photomultiplier tube, converts it into an ozone concentration signal, displays the ozone concentration and uploads it to the upper computer.

The advantage of the present invention is that the ellipsoid light-emitting chamber is installed inside the constant temperature chamber, and the optimal temperature of chemiluminescence is maintained by utilizing the internal total reflection optical characteristics of the ellipsoid light-emitting chamber and the temperature and constant temperature characteristics of the constant temperature chamber, and the environment sample gas input pipeline, The flowmeter of the standard gas input pipeline ensures that the center of the mixture of O3 gas and NO gas is at the left focus of the ellipsoid cavity; all focal plane light is reflected in the cast aluminum ellipsoid cavity, concentrated to the right focus of the ellipsoid cavity, and passes through the ellipsoid cavity. The quartz glass lens in the middle of the ellipsoid is concentrated on the photomultiplier tube window of the other focus, which improves the detection limit of ozone, and the light utilization rate exceeds 90%. A detachable constant temperature chamber is set up to facilitate regular inspection and maintenance of the ellipsoid cavity and cleaning of the quartz glass lens.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of a trace ozone concentration measuring device

Fig. 2 sectional view of an ellipsoid light-emitting chamber of a trace ozone concentration measuring device

Figure 3 is a block diagram of circuit connection of a trace ozone concentration measuring device.

In the picture 1. Left ellipsoid spherical shell, 2. Exhaust pipe, 3. Standard gas input pipe, 4. Left and right ellipsoid spherical shell under six flange ears, 5. Quartz glass lens, 6. Shading photomultiplier Tube, 7. Right ellipsoid spherical shell, 8. Left and right ellipsoid spherical shell on six flange ears, 9. Environmental sample gas input pipeline, 10. Detachable constant temperature chamber, 11. MCU microprocessor, 12. Display Screen, 20, Exhaust port, 22, Check valve, 31, Standard gas flowmeter, 32, Standard gas pressure reducing valve, 91, Sampling flowmeter, 92, Sampling peristaltic pump, 93, Sampling port with particle filter , 101, long cubic box, 102, heating rod, 103, temperature sensor, 104, upper and lower cover fixing screw seat (the upper and lower cover of the long cubic box is not drawn).

Detailed ways

Taking XHX--O3cl a kind of trace ozone concentration luminescence measurement device as an example, the description of Figure 1 in conjunction with the accompanying drawings is as follows: XHX--O3cl a kind of trace ozone luminescence measurement device The design idea is as follows, from the chemiluminescence fluorescence decay distance , determine the long axis of the inner cavity of the ellipsoid sphere, the volume of the sphere, the gas volume, the pipe diameter ratio, the velocity and the flow rate. According to the chemiluminescence manual, the fluorescence attenuation distance is 100 mm; the reflection optical path in the cavity is 2c<100 mm, so the long axis c of the ellipsoid cavity is equal to 30 mm, and the short axis a=b=20 mm. The inner diameter of the quartz glass lens is 18 mm, and it is equipped with a sealing gasket. Calculated, the volume of the inner cavity of the sphere is 50 ml. Experiments found that the particulate matter in the environmental sample gas affects chemiluminescence, so a particle filter device is added to the sampling port. The ambient sample gas is filtered through a sampling port with a particle filter device to filter out particulate matter, and the flow of the sample gas is controlled by a flow meter, and then enters the ambient sample gas input pipeline. The diameter of the ambient sample gas input pipeline is 0.20mm--1.2mm, 0.6mm is selected, the distance from the focus is 6mm, and the flow rate is 1ml/min; the diameter of the standard gas input pipeline is 3mm--12mm, and the distance is 6mm. Focus 0.6mm, flow 10ml/min. At a suitable temperature of 50 degrees Celsius, inside the ellipsoid reaction chamber, the ambient sample gas input pipe is thin Ø=0.6 mm, and the outlet end is 6 mm away from the focus; the standard gas input pipe is thick Ø=6 mm, and the outlet end is 0.6 mm away from the focus. The two gases are set opposite to each other along the radius passing through the focus. The intersection point of the two gases is near the focus, and the NO gas wraps the O3 gas; NO reacts with O3 to generate excited NO2* molecules, but the NO2* molecules cannot exist stably, and will rapidly decay to the ground state. NO2, the time is less than 1 nanosecond, and radiates fluorescence with a central wavelength of 1200 nm, its spectral range is 600-3000 nm, and the luminous point is near the focus; the exhaust pipe is perpendicular to the ambient sample gas input pipe and the standard gas input pipe. , the exhaust pipe points to the focal point, the two gases are discharged from the exhaust pipe after the intersection, and the gas luminous band is also on the focal plane of the left ellipsoid; by adjusting the distance between the ambient sample gas input pipe and the standard gas input pipe, and Adjust the flow rate to ensure that the center of the NO gas injected by the O3 gas, all the O3 gas emits light, reflects through the ellipsoid cavity, passes through the quartz glass lens, and all the light reaches the photomultiplier tube, where it is converted into a voltage signal. %. The voltage signal strength is proportional to the optical signal strength. The voltage signal goes through linear amplification, analog-to-digital conversion, and enters the MCU minimum system. MCU minimum system output O3 gas concentration. Experimental test, the detected concentration of O3 gas is 0.01-0.05ppb. The detection limit is an order of magnitude higher than that of the spherical reaction chamber.

The advantages of the present invention are that the ellipsoid light-emitting chamber is installed inside the constant temperature chamber, and the optimal temperature of chemiluminescence is maintained by utilizing the optical characteristics of total reflection inside the ellipsoid and the temperature and constant temperature characteristics of the constant temperature chamber, and the environmental sample gas input pipeline, the standard gas are controlled. The flowmeter of the input pipeline ensures that the center of the mixture of O3 gas and NO gas is at the left focus of the ellipsoid cavity; all focal plane light is reflected in the cast aluminum ellipsoid cavity, concentrated to the right focus of the ellipsoid cavity, and passes through the ellipsoid. The middle quartz glass lens is concentrated on the photomultiplier tube window of the other focus, which improves the detection limit of ozone, and the light utilization rate exceeds 90%. A detachable constant temperature chamber is set up to facilitate regular inspection and maintenance of the ellipsoid cavity and cleaning of the quartz glass lens.

Claims (2)

1. A trace ozone concentration measuring device, characterized in that the detachable ellipsoid light-emitting chamber of the ozone concentration measuring device is installed inside the detachable constant temperature chamber (10); the shape of the detachable constant temperature chamber (10) is The long cubic box (101), the long axis of the ellipsoid light-emitting chamber is along the long side direction of the long cubic box (101), the long side of the long cubic box (101) is greater than twice the long axis of the ellipsoid light-emitting chamber, the long cubic box ( The lengths of the two short sides of 101) are the same, and the length of the short side of the long cubic box (101) is greater than twice the short axis of the ellipsoid light-emitting chamber; The upper and lower covers of (101) are movable covers, and the upper and lower covers are fixed with four-cornered screws with sealing gaskets; a heating rod (102) and a temperature sensor (103) are also provided inside the long cubic box (101), and the heating rod (102) and the temperature sensor (103) are electrically connected to the MCU microprocessor (11), and the MCU microprocessor (11) controls the internal constant temperature of the detachable constant temperature chamber (10); preferably, the internal temperature of the detachable constant temperature chamber (10) is suitable for In the temperature section where the excited NO2* fluorescence is generated; the preferred ellipsoid 2 times the long axis is less than or equal to the fluorescence propagation distance of 100 mm; the detachable ellipsoid light-emitting chamber includes a left ellipsoid shell (1), a left and right ellipsoid Outer shell under six flange ears (4), quartz glass lens (5), right ellipsoid shell (7), left and right ellipsoid shell outside six flange ears (8); left ellipsoid shell ( 1) and the right ellipsoid shell (7) are cast aluminum ellipsoid shells, and the inside of the cast aluminum ellipsoid shell is polished; as shown in Figure 2, the left ellipsoid shell (1) and the right ellipsoid shell ( 7) Add the quartz glass lens (5) between the left ellipsoid shell (1) and the right ellipsoid shell (7) through the six outer flange ears (4) and the six flange ears (7) ) Mechanical connection with threaded through-hole bolts, the left ellipsoid spherical shell (1) and the right ellipsoid spherical shell (7) are closed to form a removable ellipsoid light-emitting chamber; the left ellipsoid spherical shell (1) and the quartz glass lens (5) are composed A closed light-emitting reaction chamber; on the cross-section of the focal plane x=-c of the left ellipsoid light-emitting chamber, from the horizontal line passing the focal point on the cross-section, set the opposite sealable openings clockwise, and set the standard gas input pipeline in turn (3) The environmental sample gas input pipeline (9), the environmental sample gas input pipeline (9) and the standard gas input pipeline (3) are on a diameter that passes through the focal point; it is set on the long axis of the left ellipsoid light-emitting chamber to be airtight At the opening of the hole, an exhaust pipe (2) is installed at the sealable hole; the ambient sample gas input pipe (9) and the standard gas input pipe (3) are arranged opposite to the focal plane of the left ellipsoid shell (1) x=-f, surrounding the The focal points of the ellipsoid shell are set opposite to each other, the intersection point of the two gases ozone and NO is at the focal point of the left ellipsoid shell, the NO gas wraps the ozone gas, the exhaust pipe is on the long axis of the left ellipsoid shell, and the two gases meet The mixed excitation chemiluminescence is at the focal point of the left ellipsoid shell; the quartz glass lens (5) and the right ellipsoid shell (7) form a closed photoelectric conversion room, and the right ellipsoid shell (7) is along the focal point of the ellipsoid luminescence chamber. The plane x=f is punched, and the photomultiplier tube (6 ), the optical window of the photomultiplier tube (6) is at the focus of the right ellipsoid shell; the chemiluminescence at the focus of the left ellipsoid shell (1), directly or through the internal reflection of the ellipsoid shell, passes through the left ellipsoid shell The quartz glass lens (5) between the shell (1) and the right ellipsoid shell (7) is optically connected to the photomultiplier tube (6) optical window of the focal point of the right ellipsoid shell (7); the exhaust pipe (2), The standard gas pipeline (3) and the ambient sample gas input pipeline (9) pass through the left wall of the detachable constant temperature chamber (10), wherein the ambient sample gas input pipeline (9) is connected to the inlet end of the sample gas flowmeter (91), and the sample gas The outlet end of the flow meter (91) is connected to the outlet end of the peristaltic sampling pump (92), and the inlet end of the peristaltic sampling pump (92) is connected to the sampling port (93) with a particle filter device; the standard gas input pipeline (3) is connected to the standard The inlet end of the gas flow meter (31) is connected to the standard gas pressure reducing valve (32) at the outlet end of the standard gas flow meter (31), and the standard gas pressure reducing valve (32) is connected to the standard gas source (33); the exhaust pipe (2 ) The pipeline is connected to the check valve (22), the check valve (22) is connected to the exhaust gas exhaust port (20), and the check valve (22) only allows one-way ventilation. 2. A trace ozone concentration measuring device according to claim 1, characterized in that, a standard gas pressure reducing valve (32), a peristaltic sampling pump (92), a heating rod (102), a temperature sensor (103) and The photomultiplier tube (6) is electrically connected to the MCU microprocessor (11), and the MCU microprocessor (11) is electrically connected to the display screen (12); the MCU microprocessor (11) receives the photomultiplier tube electric quantity signal and converts it into an ozone concentration signal , display the ozone concentration and upload it to the host computer.

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