Dual calibration method for dust instrument

Abstract

The invention discloses a dual calibration method for a dust instrument. The dual calibration method comprises the following steps: S1, providing a dual calibration device; S2, calibrating a static instrument; and S3, calibration of the dynamic instrument comprises the following sub-steps: S31, generating a dust environment; s32, installing a standard dust instrument and a to-be-calibrated dust instrument; s33, starting the equipment; s34, the wind speed value V1 is recorded, and a TSP to-be-calibrated 11 and a TSP standard 11 are obtained; s35, stopping sampling; s36, repeating the steps S34 and S35 for n times in total; s37, calculating a wind speed V1 and a first compensation coefficient lambda 1; s38, calculating a wind speed V1, a second compensation coefficient lambda2, a third compensation coefficient lambda3,..., and an mth compensation coefficient lambdam; s39, calculating a compensation coefficient average value # imgabs0 #; s310, adjusting the wind speed to V2; s311, a compensation coefficient average value # imgabs 1 # at the wind speed V2 is obtained; and S312, obtaining the average value of each compensation coefficient # imgabs2 #, # imgabs3 #,..., # imgabs4 #. The dual calibration method can realize the static and dynamic dual calibration of the dust instrument.

Description

Technical Field

[0001] The invention relates to the technical field of dust meter calibration, in particular to a dust meter double calibration method. Background Art

[0002] At present, the existing dust environment simulation equipment directly sends the generated dust into the relevant container, and then completes the detection through the detection unit. At the same time, the simulation equipment can also be used to calibrate the detection element (dust meter).

[0003] The applicant previously applied for a low-concentration dust environment simulation detection device, with the authorization announcement number CN217111950U. The public text records a low-concentration dust environment simulation detection device, but this simulation detection device is suitable for static calibration of dust meters, that is, the dust meter is placed in the detection room, the dust in the detection room is evenly diffused, and the dust flow is very slow, ensuring the uniformity of dust diffusion in the detection room, so that the detection and calibration results are more accurate.

[0004] However, some dust meters have special usage scenarios. For example, when detecting the concentration of smoke exhaust in a chimney, it is necessary to sample the chimney smoke at a constant speed when detecting the dust inside the smoke stack. In other words, it is necessary to sample from the chimney at a sampling speed equal to the chimney smoke exhaust speed and then input it into the dust meter for concentration detection. Therefore, the dynamic accuracy requirements for dust meters are also higher. However, the accuracy of the detection results of dust meters in a static environment cannot represent the detection accuracy in a dynamic environment. Therefore, there is currently no dual calibration device that can meet both dynamic and static requirements. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a dust meter dual calibration method, which can realize static and dynamic dual calibration of the dust meter, thereby meeting the calibration requirements of the dust meter under different sampling environments.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: a dust meter double calibration method, comprising the following steps: S1. Provide a dual calibration device, including a dust environment simulation device, the dust environment simulation device includes a frame, a detection chamber is arranged on the frame, a vertically arranged feeding tube is connected above the detection chamber, a dust generating device and a blowing mechanism are connected at the upper end of the feeding tube, and the air outlet direction of the blowing mechanism is tangent to the feeding tube; a grid plate for placing a dust meter is arranged in the detection chamber, the grid plate divides the detection chamber into an upper chamber and a lower chamber, a fixed support for fixing a sampling head of a filter membrane sampling device is also arranged on the grid plate, a first air outlet is arranged on the side wall of the lower chamber, the first air outlet is connected to a first filtering device and a first exhaust device, and the side wall of the upper chamber is provided with a first air outlet connected to a first filtering device and a first exhaust device. A second air outlet is provided on the wall, and an air supply pipe is fixedly connected to the second air outlet, and the air supply pipe is connected to the air inlet end of the horizontal wind tunnel. An ejector of a jet pump is provided in the air supply pipe, and the outlet of the ejector is connected to the horizontal wind tunnel, and the air suction port of the jet pump is connected to the air supply pipe. A second filtering device and a second air exhausting device are connected to the downstream of the horizontal wind tunnel. A wind speed detector and a detection head installation window are provided on the horizontal wind tunnel, and the horizontal wind tunnel includes an expanded pipe section and a horizontal uniform flow straight pipe section. The detection head installation window and the wind speed detector are both provided on the horizontal uniform flow straight pipe section, and the detection head installation window is used to fix the sampling head of the standard dust meter and the sampling head of the dust meter to be calibrated; S2. Calibration of static instruments includes the following steps: S21, the dust generating device generates dust quantitatively and blows the particles into the feeding tube through the blowing mechanism; the first exhaust device exhausts the lower chamber to generate negative pressure in the detection chamber, so that the dust-containing gas enters the detection chamber through the feeding tube and diffuses evenly to form a uniform dust environment; S22. Place the dust meter to be calibrated on the grid plate, fix the sampling head of the filter membrane sampling device on the fixed support, and weigh the unused filter membrane in advance to obtain W. 前 ; S23, the dust meter to be calibrated and the filter membrane sampling device start sampling at the same time and use the set time t. The dust concentration obtained by the dust meter to be calibrated is TSP 待校准 ; S24, take out the filter membrane in the filter membrane sampling device and weigh it to obtain a weight W 后 , through the formula TSP 滤 =(W 后 -W 前 ) / Q 滤 t, where Q 滤 is the sampling flow rate of the membrane sampling device; S25, repeat steps S23 and S24 to obtain multiple groups of TSP 待校准 and TSP 滤, calibrate the dust meter to be calibrated by adjusting the static compensation coefficient by one-to-one comparison; S3. The calibration of dynamic instruments includes the following steps: S31, the dust generating device generates dust quantitatively and blows the particles into the feeding tube through the blowing mechanism; the first exhaust device exhausts the lower chamber to generate negative pressure in the detection chamber, so that the dust-containing gas enters the detection chamber through the feeding tube and diffuses evenly to form a uniform dust environment; S32, insert the sampling heads of the standard dust meter and the dust meter to be calibrated into the horizontal wind tunnel through the detection head installation window; S33, the second air extraction device and the jet pump are started simultaneously, and the jet pump draws the dust-containing gas in the detection room from the second air outlet into the air supply pipe and into the horizontal wind tunnel; S34, after the jet pump and the second exhaust device continue to work for a set time, the sampling head of the standard dust meter and the sampling head of the dust meter to be calibrated are started at the same time and sampling is carried out at the same sampling speed as the wind speed detected by the wind speed detector. The sampling time is T 采1 , record the wind speed value V1 in the current wind speed detector, and obtain the dust concentration value TSP under the current wind speed V1 待校准11 and TSP 标准11 ; S35, the sampling head of the standard dust meter and the dust meter to be calibrated stop sampling set time T 停 ; S36, repeat steps S34 and S35 for n times, and obtain a total dust concentration value TSP 待校准11 and TSP 标准11 , dust concentration value TSP 待校准12 and TSP 标准12 , ..., dust concentration value TSP 待校准1n and TSP 标准1n ; S37, calculate the TSP at wind speed V1 待校准 The average and , compare and By adjusting the first compensation coefficient λ1 of the dust meter to be calibrated and equal, temporarily save the corresponding relationship between the current wind speed V1 and the first compensation coefficient λ1 into the dust meter to be calibrated; S38, change the dust generation amount of the dust generating device, and continue to repeat steps S34 to S37 for a total of m times, and obtain the dust generation amount under the wind speed V1 again. and , and ,……, and ; and adjust the second compensation coefficients λ2, λ3, ..., λ of the dust meter to be calibrated respectively m make and equal, and equal,……, and equal to the current wind speed V1 and the second compensation coefficient λ2, the third compensation coefficient λ3, ..., the mth compensation coefficient λ m The corresponding relationship is temporarily saved in the dust meter to be calibrated; S39. Calculate λ1, λ2,...,λ m The average compensation coefficient , and finally the current wind speed V1 and the average value of the compensation coefficient The corresponding relationship is saved in the dust meter to be calibrated; S310, changing the suction power of the second suction device, while the jet pump continues to work, and the wind speed detector continues to detect the wind speed until the wind speed reaches V2 and stabilizes for a certain duration; S311, repeat steps S34 to S39 to obtain the average value of the compensation coefficient at the wind speed V2 , and finally the current wind speed V2 and the average value of the compensation coefficient The corresponding relationship is saved in the dust meter to be calibrated; S312, continue to repeat steps S310 and S311 for a total of k times, so as to obtain k Average value of compensation coefficients under wind speed , ,……, ; and finally save the corresponding relationship between the current wind speed and the average value of the compensation coefficient to the dust meter to be calibrated to complete the calibration; when the calibrated dust meter is performing dynamic dust environment monitoring, the average value of the compensation coefficient corresponding to the wind speed with the smallest wind speed difference is selected as the current compensation coefficient according to the wind speed of the dynamic dust environment.

[0007] As a preferred solution, an upper cover plate is detachably installed on the detection head installation window, and a first sampling tube and a second sampling tube are pre-fixed on the upper cover plate. The lower ends of the first sampling tube and the second sampling tube extend into the interior of the horizontal uniform flow straight pipe section, and the lower end pipe openings of the first sampling tube and the second sampling tube are horizontally arranged and face the air inlet side. When dynamic calibration is required, the upper ends of the first sampling tube and the second sampling tube are respectively connected to the sampling head of the standard dust meter and the sampling head of the dust meter to be calibrated. In this way, the connection during calibration is simpler.

[0008] As a preferred solution, the wind speeds V1, V2, ..., Vk is an arithmetic progression.

[0009] As a preferred solution, the lower end opening of the first sampling tube and the lower end opening of the second sampling tube are on the same cross-section, the lower end opening of the first sampling tube and the lower end opening of the second sampling tube are close to the center of the horizontal uniform flow straight pipe section and are arranged symmetrically on the left and right, and the sampling area is also the most uniform part of the horizontal uniform flow straight pipe section, so that the sampling error of the first sampling tube and the second sampling tube is smaller, and the interference between them is also smaller.

[0010] As a preferred solution, the horizontal uniform flow straight pipe section is also provided with a temperature probe and a humidity probe, and the expanded pipe section is also provided with an air supply port for replenishing warm and humid air. The air supply port is connected to the warm and humid air supply system, and the warm and humid air is replenished in the horizontal wind tunnel through the warm and humid air supply system. The temperature and humidity correspondences of different temperatures and humidities are set, and step S3 is repeated under each temperature and humidity correspondence to obtain the average compensation coefficient of different wind speeds under each temperature and humidity correspondence. When monitoring the dynamic dust environment, the temperature, humidity and wind speed of the dynamic dust environment are detected, and the average compensation coefficient with the smallest difference from the detected temperature, humidity and wind speed is selected as the current compensation coefficient. Therefore, the dust environment under different temperatures, humidity and wind speeds can be simulated in the horizontal wind tunnel, so that more factors are considered during calibration, and the calibration effect is better and more accurate.

[0011] As a preferred scheme, in the step of selecting the average compensation coefficient with the smallest average difference between the detected temperature, humidity and wind speed as the current compensation coefficient: first consider the humidity difference, then the temperature difference, and finally the wind speed difference, and select the average compensation coefficient with the smallest average difference according to the above selection principle.

[0012] After adopting the above technical scheme, the effects of the present invention are: 1. The dual calibration method can sample and calibrate the instrument in a static environment or perform isokinetic sampling and calibration in a dynamic flow environment. The particle distribution in the static or dynamic environment is uniform, ensuring the accuracy of the calibration result; 2. In the dual calibration method, when calibrating in a dynamic environment, multiple calibrations are performed according to different wind speeds, and then the average value of the compensation coefficient under the current wind speed is calculated. In this way, when the dust meter is used for dynamic monitoring and sampling in the subsequent use, the appropriate compensation coefficient can be selected according to the wind speed of the dynamic environment for compensation, so that the sampling results during dynamic monitoring are more accurate and the error is smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0014] Figure 1 is a structural stereogram of a dual calibration device in the method of the present invention; Figure 2 is a schematic diagram of the side structure of the dual calibration device; Figure 3 It is a three-dimensional diagram of a dust environment simulation device; Figure 4 It is a structural stereogram of a horizontal wind tunnel; Figure 5 It is a schematic diagram of the end face of a horizontal wind tunnel; Figure 6 yes Figure 5 Sectional view at AA; In the attached drawings: 1. frame; 2. feeding barrel; 21. air supply hood; 22. conical cylinder; 23. straight cylinder; 24. neck; 3. detection chamber; 31. upper chamber; 32. lower chamber; 4. dust generating device; 5. blowing mechanism; 51. blower; 52. filter barrel; 53. air supply pipe; 6. first air outlet; 7. air supply pipe; 71. straight pipe section; 72. closing pipe section; 8. control box; 81. jet pump; 9. horizontal wind tunnel; 91. flared pipe section; 92. horizontal uniform flow straight pipe section; 93. detection head installation window; 94. upper cover plate; 95. first sampling tube; 96. second sampling tube; 10. wind speed detector; 11. movable bracket; 12. second filtering device; 13. fixed support. DETAILED DESCRIPTION

[0015] The present invention is further described in detail below through specific examples.

[0016] A dust meter double calibration method comprises the following steps: S1. Provide a dual calibration device, including a dust environment simulation device, the dust environment simulation device includes a frame 1, a detection chamber 3 is provided on the frame 1, a vertically arranged feeding barrel 2 is connected to the top of the detection chamber 3, a dust generating device 4 and a blowing mechanism 5 are connected to the upper end of the feeding barrel 2, and the air outlet direction of the blowing mechanism 5 is tangent to the feeding barrel 2; a grid plate for placing a dust meter is provided in the detection chamber 3, the grid plate divides the detection chamber 3 into an upper chamber 31 and a lower chamber 32, and a fixed support 13 for fixing the sampling head of the filter membrane sampling device is also provided on the grid plate, a first air outlet 6 is provided on the side wall of the lower chamber 32, the first air outlet 6 is connected to the first filtering device and the first exhaust device, a second air outlet is provided on the side wall of the upper chamber 31, and an air supply pipe 7 is fixedly connected to the second air outlet, and the air supply pipe 7 includes a straight pipe section 71 and a collecting The outlet pipe section 72, the ejector of the jet pump 81 is fixed in the straight pipe section 71, the compressed air inlet of the ejector is arranged at the bottom of the straight pipe section 71, the air supply pipe 7 is connected with the air inlet end of the horizontal wind tunnel 9, the ejector of the jet pump 81 is arranged in the air supply pipe 7, the outlet of the ejector is connected with the horizontal wind tunnel 9, the air suction port of the jet pump 81 is connected with the air supply pipe 7, the downstream of the horizontal wind tunnel 9 is connected with a second filtering device 12 and a second air extraction device, the horizontal wind tunnel 9 is fixed on the mobile bracket 11, the horizontal wind tunnel 9 is provided with a wind speed detector 10 and a detection head installation window 93, the horizontal wind tunnel 9 includes an expanded pipe section 91 and a horizontal uniform flow straight pipe section 92, the detection head installation window 93 and the wind speed detector 10 are both arranged on the horizontal uniform flow straight pipe section 92, the detection head installation window 93 is used to fix the sampling head of the standard dust meter and the sampling head of the dust meter to be calibrated; S2. Calibration of static instruments includes the following steps: S21, the dust generating device 4 generates dust quantitatively and blows the particles into the feeding tube 2 through the blowing mechanism 5; the first exhaust device exhausts the lower chamber 32 to generate negative pressure in the detection chamber 3, so that the dust-containing gas enters the detection chamber through the feeding tube 2 and diffuses evenly to form a uniform dust environment; S22. Place the dust meter to be calibrated on the grid plate, and fix the sampling head of the filter membrane sampling device on the fixed support 13. The filter membrane sampling device is a conventional device at present. Its principle is to sample the dust-containing gas in the detection chamber through a sampling pump. The particles will be filtered after the sampled gas passes through the filter membrane. Weigh the unused filter membrane in advance to obtain W 前 ; S23, the dust meter to be calibrated and the filter membrane sampling device start sampling at the same time and use the set time t. The dust concentration obtained by the dust meter to be calibrated is TSP 待校准 ; S24, take out the filter membrane in the filter membrane sampling device and weigh it to obtain a weight W 后 , through the formula TSP 滤 =(W 后 -W 前 ) / Q 滤 t, where Q 滤 is the sampling flow rate of the membrane sampling device; S25, repeat steps S23 and S24 to obtain multiple groups of TSP 待校准 and TSP 滤 , calibrate the dust meter to be calibrated by adjusting the static compensation coefficient by one-to-one comparison; S3. The calibration of dynamic instruments includes the following steps: S31, the dust generating device 4 generates dust quantitatively and blows the particles into the feeding tube 2 through the blowing mechanism 5; the first exhaust device exhausts the lower chamber 32 to generate negative pressure in the detection chamber 3, so that the dust-containing gas enters the detection chamber through the feeding tube 2 and diffuses evenly to form a uniform dust environment. The first exhaust device uses an exhaust fan and is equipped with a first filter device to ensure that clean gas is discharged; S32. Extend the sampling heads of the standard dust meter and the dust meter to be calibrated from the detection head installation window 93 into the horizontal wind tunnel 9. In this embodiment, an upper cover plate 94 is detachably installed on the detection head installation window 93, and a first sampling tube 95 and a second sampling tube 96 are pre-fixed on the upper cover plate 94. The lower ends of the first sampling tube 95 and the second sampling tube 96 extend into the interior of the horizontal uniform flow straight pipe section 92. The lower end openings of the first sampling tube 95 and the second sampling tube 96 are horizontally arranged and face the air inlet side. When dynamic calibration is required, the upper ends of the first sampling tube 95 and the second sampling tube 96 are connected to the sampling head of the standard dust meter and the sampling head of the dust meter to be calibrated, respectively. In this way, the connection during calibration is simpler.

[0017] The lower end of the first sampling tube 95 and the lower end of the second sampling tube 96 are on the same cross section, the lower end of the first sampling tube 95 and the lower end of the second sampling tube 96 are close to the center of the horizontal uniform flow straight tube section 92 and are arranged symmetrically, and the sampling area is also the most uniform part of the horizontal uniform flow straight tube section 92, so that the sampling error of the first sampling tube 95 and the second sampling tube 96 is smaller, and the interference between them is also small. In this way, the state of sampling detection inside the chimney or pipeline can be fully simulated during dynamic calibration.

[0018] S33, the second air extraction device and the jet pump 81 are started simultaneously, and the jet pump 81 draws the dust-containing gas in the detection chamber 3 from the second air outlet into the air supply pipe 7 and into the horizontal wind tunnel 9; S34, after the jet pump 81 and the second exhaust device continue to work for a set time, the dust discharge environment inside the horizontal wind tunnel 9 is relatively stable, the sampling head of the standard dust meter and the sampling head of the dust meter to be calibrated are started at the same time and sampled at the same sampling speed as the wind speed detected by the wind speed detector 10, and the sampling time is T 采1 , record the wind speed value V1 in the current wind speed detector 10, and obtain the dust concentration value TSP under the current wind speed V1 待校准11 and TSP 标准11 ; S35, the sampling head of the standard dust meter and the dust meter to be calibrated stop sampling set time T 停 ; And because the stop time is set, it is possible to avoid concentrated sampling errors caused by particle fluctuations within a certain period of time.

[0019] S36, repeat steps S34 and S35 for n times, and obtain a total dust concentration value TSP 待校准11 and TSP 标准11 , dust concentration value TSP 待校准12 and TSP 标准12 , ..., dust concentration value TSP 待校准1n and TSP 标准1n ; S37, calculate the TSP at wind speed V1 待校准 The average and , compare and By adjusting the first compensation coefficient λ1 of the dust meter to be calibrated and equal, temporarily save the corresponding relationship between the current wind speed V1 and the first compensation coefficient λ1 into the dust meter to be calibrated; S38, change the dust generation amount of the dust generating device 4, and continue to repeat steps S34 to S37 for a total of m times, and obtain the dust generation amount under the wind speed V1 again. and , and ,……, and ; and adjust the second compensation coefficients λ2, λ3, ..., λ of the dust meter to be calibrated respectively m make and equal, and equal,……, and equal to the current wind speed V1 and the second compensation coefficient λ2, the third compensation coefficient λ3, ..., the mth compensation coefficient λ mThe corresponding relationship is temporarily saved in the dust meter to be calibrated; S39. Calculate λ1, λ2,...,λ m The average compensation coefficient , and finally the current wind speed V1 and the average value of the compensation coefficient The corresponding relationship is saved in the dust meter to be calibrated; S310, changing the air extraction power of the second air extraction device, while the jet pump 81 continues to work, and the wind speed detector 10 continues to detect the wind speed until the wind speed reaches V2 and stabilizes for a certain duration; S311, repeat steps S34 to S39 to obtain the average value of the compensation coefficient at the wind speed V2 , and finally the current wind speed V2 and the average value of the compensation coefficient The corresponding relationship is saved in the dust meter to be calibrated; S312, continue to repeat steps S310 and S311 for a total of k times, so as to obtain k Average value of compensation coefficients under wind speed , ,……, ; and finally save the corresponding relationship between the current wind speed and the average value of the compensation coefficient to the dust meter to be calibrated to complete the calibration; when the calibrated dust meter is performing dynamic dust environment monitoring, the average value of the compensation coefficient corresponding to the wind speed with the smallest wind speed difference is selected as the current compensation coefficient according to the wind speed of the dynamic dust environment.

[0020] The wind speeds V1, V2, ..., V k is an arithmetic progression.

[0021] The horizontal uniform flow straight pipe section 92 is also provided with a temperature probe and a humidity probe, and the expanded pipe section 91 is also provided with an air supply port for replenishing warm and humid air. The air supply port is connected to the warm and humid air supply system, and the warm and humid air is replenished into the horizontal wind tunnel 9 through the warm and humid air supply system. The temperature and humidity correspondences of different temperatures and humidities are set, and step S3 is repeated under each temperature and humidity correspondence to obtain the average value of the compensation coefficients for different wind speeds under each temperature and humidity correspondence. When monitoring the dynamic dust environment, the temperature, humidity and wind speed of the dynamic dust environment are detected, and the average value of the compensation coefficient with the smallest difference from the detected temperature, humidity and wind speed is selected as the current compensation coefficient. Therefore, the dust environment under different temperatures, humidity and wind speeds can be simulated in the horizontal wind tunnel 9, so that more factors are considered during calibration, and the calibration effect is better and more accurate. In the step of selecting the average compensation coefficient with the smallest average difference between the detected temperature, humidity and wind speed as the current compensation coefficient: first consider the humidity difference, then the temperature difference, and finally the wind speed difference, and select the average compensation coefficient with the smallest average difference according to the above selection principle.

[0022] like Figures 1 to 6 As shown, the accompanying drawings disclose a dual calibration device for a dust meter, including a dust environment simulation device, the dust environment simulation device includes a frame 1, a detection chamber 3 is provided on the frame 1, and a vertically arranged feeding barrel 2 is connected above the detection chamber 3, wherein the feeding barrel 2 includes a straight barrel portion 23 and a conical barrel portion 22, the straight barrel portion 23 is connected to the detection chamber 3, the large end of the conical barrel portion 22 is connected to the straight barrel portion 23, an air supply hood 21 is provided at the upper end of the conical barrel section, and a closed neck 24 is provided at the lower end of the air supply hood 21 and is connected to the small diameter end of the conical barrel portion 22.

[0023] The upper end of the feeding barrel 2 is connected to a dust generating device 4 and a blowing mechanism 5, and the air outlet direction of the blowing mechanism 5 is tangent to the feeding barrel 2; wherein, the specific structure of the dust generating device 4 can be seen in detail in the scheme recorded in CN202020319771.8, and the blowing mechanism 5 includes an air supply pipe 53, and the upper end of the air supply pipe 53 is connected to the air supply hood 21; a fan box is also fixed on the frame 1, and the fan box is arranged on one side of the feeding barrel 2, and a blower 51 is arranged in the fan box, and the blower 51 is connected to a filter cartridge 52, and the filter cartridge 52 is connected to the air supply pipe 53, so as to provide clean air and provide air supply power.

[0024] A grid plate for placing a dust meter is provided in the detection chamber 3, and the grid plate divides the detection chamber 3 into an upper chamber 31 and a lower chamber 32. The grid plate is also provided with a fixed support 13 for fixing the sampling head of the filter membrane sampling device. A first air outlet 6 is provided on the side wall of the lower chamber 32, and the first air outlet 6 is connected to a first filtering device and a first exhaust device. The first exhaust device generates a negative pressure in the detection chamber 3, so that the feeding pipe conveys dust-containing air downward, and the first exhaust device sucks the dust-containing air at the same time, thereby forming an air flow balance, so that the particulate matter is evenly diffused in the detection chamber 3.

[0025] A second air outlet is provided on the side wall of the upper chamber 31, and an air supply pipe 7 is fixedly connected to the second air outlet. The air supply pipe 7 is connected to the air inlet end of the horizontal wind tunnel 9. An ejector of a jet pump 81 is provided in the air supply pipe 7, and the outlet of the ejector is connected to the horizontal wind tunnel 9. The air suction port of the jet pump 81 is connected to the air supply pipe 7, and the jet pump 81 is fixed in a control box 8, and the control box 8 is fixed on the air supply pipe 7. A second filtering device 12 and a second air extraction device are connected to the downstream of the horizontal wind tunnel 9. A wind speed detector 10 and a detection head installation window 93 are provided on the horizontal wind tunnel 9. The horizontal wind tunnel 9 includes an expanded pipe section 91 and a horizontal uniform flow straight pipe section 92. The detection head installation window 93 and the wind speed detector 10 are both arranged on the horizontal uniform flow straight pipe section 92. The detection head installation window 93 is used to fix the sampling head of the standard dust meter and the sampling head of the dust meter to be calibrated; The above-described embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Various modifications and alterations to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A dust meter dual calibration method, characterized in that: The following steps are involved: S1. Provide a dual calibration device, including a dust environment simulation device, the dust environment simulation device includes a frame, a detection chamber is arranged on the frame, a vertically arranged feeding tube is connected above the detection chamber, a dust generating device and a blowing mechanism are connected at the upper end of the feeding tube, and the air outlet direction of the blowing mechanism is tangent to the feeding tube; a grid plate for placing a dust meter is arranged in the detection chamber, the grid plate divides the detection chamber into an upper chamber and a lower chamber, a fixed support for fixing a sampling head of a filter membrane sampling device is also arranged on the grid plate, a first air outlet is arranged on the side wall of the lower chamber, the first air outlet is connected to a first filtering device and a first exhaust device, and the side wall of the upper chamber is provided with a first air outlet connected to a first filtering device and a first exhaust device. A second air outlet is provided on the wall, and an air supply pipe is fixedly connected to the second air outlet, and the air supply pipe is connected to the air inlet end of the horizontal wind tunnel. An ejector of a jet pump is provided in the air supply pipe, and the outlet of the ejector is connected to the horizontal wind tunnel, and the air suction port of the jet pump is connected to the air supply pipe. A second filtering device and a second air exhausting device are connected to the downstream of the horizontal wind tunnel. A wind speed detector and a detection head installation window are provided on the horizontal wind tunnel, and the horizontal wind tunnel includes an expanded pipe section and a horizontal uniform flow straight pipe section. The detection head installation window and the wind speed detector are both provided on the horizontal uniform flow straight pipe section, and the detection head installation window is used to fix the sampling head of the standard dust meter and the sampling head of the dust meter to be calibrated; S2. Calibration of static instruments includes the following steps: S21, the dust generating device generates dust quantitatively and blows the particles into the feeding tube through the blowing mechanism; the first exhaust device exhausts the lower chamber to generate negative pressure in the detection chamber, so that the dust-containing gas enters the detection chamber through the feeding tube and diffuses evenly to form a uniform dust environment; S22. Place the dust meter to be calibrated on the grid plate, fix the sampling head of the filter membrane sampling device on the fixed support, and weigh the unused filter membrane in advance to obtain W. 前 ; S23. The dust meter to be calibrated and the filter membrane sampling device start sampling at the same time and use the set time t. The dust concentration obtained by the dust meter to be calibrated is TSP 待校准 ; S24, take out the filter membrane in the filter membrane sampling device and weigh it to obtain a weight W 后 , through the formula TSP 滤 =(W 后 -W 前 ) / Q 滤 t, where Q 滤 is the sampling flow rate of the membrane sampling device; S25, repeat steps S23 and S24 to obtain multiple groups of TSP 待校准 and TSP 滤 , calibrate the dust meter to be calibrated by adjusting the static compensation coefficient by one-to-one comparison; S3. The calibration of dynamic instruments includes the following steps: S31, the dust generating device generates dust quantitatively and blows the particles into the feeding tube through the blowing mechanism; the first exhaust device exhausts the lower chamber to generate negative pressure in the detection chamber, so that the dust-containing gas enters the detection chamber through the feeding tube and diffuses evenly to form a uniform dust environment; S32, insert the sampling heads of the standard dust meter and the dust meter to be calibrated into the horizontal wind tunnel through the detection head installation window; S33, the second air extraction device and the jet pump are started simultaneously, and the jet pump draws the dust-containing gas in the detection room from the second air outlet into the air supply pipe and into the horizontal wind tunnel; S34, after the jet pump and the second exhaust device continue to work for a set time, the sampling head of the standard dust meter and the sampling head of the dust meter to be calibrated are started at the same time and sampling is carried out at the same sampling speed as the wind speed detected by the wind speed detector. The sampling time is T 采1 , record the wind speed value V1 in the current wind speed detector, and obtain the dust concentration value TSP under the current wind speed V1 待校准11 and TSP 标准11 ; S35, the sampling head of the standard dust meter and the dust meter to be calibrated stop sampling set time T 停 ; S36, repeat steps S35 and S36 for n times, and obtain a dust concentration value TSP 待校准11 and TSP 标准11 , dust concentration value TSP 待校准12 and TSP 标准12 , ..., dust concentration value TSP 待校准1n and TSP 标准1n ; S37, calculate the TSP at wind speed V1 待校准 The average and , compare and By adjusting the first compensation coefficient λ1 of the dust meter to be calibrated and equal, temporarily save the corresponding relationship between the current wind speed V1 and the first compensation coefficient λ1 into the dust meter to be calibrated; S38, change the dust generation amount of the dust generating device, and continue to repeat steps S34 to S37 for a total of m times, and obtain the dust generation amount under the wind speed V1 again. and , and ,……, and ; And adjust the second compensation coefficients λ2, λ3, ..., λ of the dust meter to be calibrated respectively. m make and equal, and equal,……, and equal to the current wind speed V1 and the second compensation coefficient λ2, the third compensation coefficient λ3, ..., the mth compensation coefficient λ m The corresponding relationship is temporarily saved in the dust meter to be calibrated; S39. Calculate λ1, λ2,...,λ m The average compensation coefficient , and finally the current wind speed V1 and the average value of the compensation coefficient The corresponding relationship is saved in the dust meter to be calibrated; S310, changing the suction power of the second suction device, while the jet pump continues to work, and the wind speed detector continues to detect the wind speed until the wind speed reaches V2 and stabilizes for a certain duration; S311, repeat steps S34 to S39 to obtain the average value of the compensation coefficient at the wind speed V2 , and finally the current wind speed V2 and the average value of the compensation coefficient The corresponding relationship is saved in the dust meter to be calibrated; S312, continue to repeat steps S310 and S311 for a total of k times, so as to obtain k Average value of compensation coefficients under wind speed , ,……, ; Finally, the corresponding relationship between the current wind speed and the average value of the compensation coefficient is saved in the dust meter to be calibrated to complete the calibration; When the calibrated dust meter is performing dynamic dust environment monitoring, the average compensation coefficient corresponding to the wind speed with the smallest wind speed difference is selected as the current compensation coefficient according to the wind speed of the dynamic dust environment.

2. A dust meter dual calibration method as claimed in claim 1, characterized in that: An upper cover plate is detachably mounted on the detection head mounting window, and a first sampling tube and a second sampling tube are pre-fixed on the upper cover plate. The lower ends of the first sampling tube and the second sampling tube extend into the interior of the horizontal uniform flow straight pipe section, and the lower end openings of the first sampling tube and the second sampling tube are horizontally arranged and face the air inlet side. When dynamic calibration is required, the upper ends of the first sampling tube and the second sampling tube are respectively connected to the sampling head of the standard dust meter and the sampling head of the dust meter to be calibrated.

3. A dust meter dual calibration method as claimed in claim 1, characterized in that: The wind speeds V1, V2, ..., V k is an arithmetic progression.

4. A dust meter dual calibration method as claimed in claim 2, characterized in that: The lower end opening of the first sampling tube and the lower end opening of the second sampling tube are located on the same cross section, and the lower end opening of the first sampling tube and the lower end opening of the second sampling tube are close to the center of the horizontal uniform flow straight pipe section and are arranged symmetrically.

5. A dust meter dual calibration method as claimed in claim 1, characterized in that: The horizontal uniform flow straight pipe section is also provided with a temperature probe and a humidity probe, and the expanded pipe section is also provided with an air supply port for replenishing warm and humid air. The air supply port is connected to the warm and humid air supply system, and the warm and humid air is replenished in the horizontal wind tunnel through the warm and humid air supply system. The temperature and humidity correspondence relationship of different temperatures and humidities is set, and step S3 is repeated under each temperature and humidity correspondence relationship to obtain the average value of the compensation coefficient for different wind speeds under each temperature and humidity correspondence relationship. When performing dynamic dust environment monitoring, the temperature, humidity and wind speed of the dynamic dust environment are detected, and the average value of the compensation coefficient with the smallest difference from the detected temperature, humidity and wind speed is selected as the current compensation coefficient.

6. A dust meter dual calibration method as claimed in claim 5, characterized in that: In the step of selecting the average compensation coefficient with the smallest average difference between the detected temperature, humidity and wind speed as the current compensation coefficient: first consider the humidity difference, then the temperature difference, and finally the wind speed difference, and select the average compensation coefficient with the smallest average difference according to the above selection principle.

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