GB/T 39193-2020 Gravimetric method for determination of mass concentration of particulate matter in ambient air GB/T39193-2020 |tt||Standard compression package decompression password: www.bzxz.net
This standard specifies the method for sampling and weighing the ambient air particulate matter filter membrane, including principles and methods, instruments and equipment, sampling and weighing, calculation and expression of results, uncertainty assessment of measurement results, quality control and quality assurance. This standard is applicable to the measurement of the mass concentration of particulate matter in ambient air using the filter membrane weighing method.

ICS 19.120
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National Standard of the People's Republic of China
GB/T 39193—2020
Ambient air
Determination of particulate matter mass concentration
Gravimetric method
Ambient air--Determination of particulate matter mass concentrationGravimetric method2020-10-11 release
State Administration for Market Regulation
National Standardization Administration
2021-05-01 implementation
Normative reference documents
Terms and definitions
Original and final method
Instruments and equipment
Sampling and weighing
Result measurement and expression
Uncertainty assessment of measurement results
Quality control and quality assurance
Appendix A (Normative Appendix) Sampler airtightness test method Appendix (Normative Appendix) Sampler flow rate test method
Appendix ((Informative Appendix) Title Example of uncertainty assessment of particle mass concentration measurement Literature
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GB/T 39193—2020
This standard is issued in accordance with the rules given in GB/T1.1—2019. iiikAa~cJouakAa
GB/T39193—2020
This standard is proposed and managed by the National Technical Committee for Particle Characterization and Sorting and Screen Standardization (SAC/TC168). Drafting units of this standard: China Institute of Metrology, Qingdao Institute of Metrology and Technology, China National Environmental Monitoring Center, Sichuan East Mente Instrument Co., Ltd., China Meteorological Science Research Institute, China Environmental Science Institute, Qingdao Zhongduan Intelligent Instrument Co., Ltd., Shenzhen Guoji Instrument Co., Ltd., Henan Institute of Metrology, Zhejiang Duopu Environmental Protection Technology Co., Ltd., Zhejiang Ruixue Plastic Technology Co., Ltd., Beijing Modern Analysis and Testing Center, Institute of Process Engineering, Chinese Academy of Sciences, Beijing Powder Technology Association, Qingdao Laoying Environmental Technology Co., Ltd., South China Normal University, Qingdao Rongguang Technology Co., Ltd., China University of Planning, China Machine Productivity Visualization Center, the main drafters of this standard: Zhang Yishang, Xu Qian, Liu Wei, Qiang, Dong Shiyun, Yan Peng, Yang Wen, Lu Xingjie, He Chunxu GB/T39193—2020
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Particulate matter in ambient air (TSPPM: PM, etc.) is a common pollutant. It has a significant impact on human health, visibility and ecology. Therefore, the mass concentration measurement of this type of pollutant is an important part of environmental research. Methods include; gravimetric method, micro-oscillation gravimetric method (TI(M) method, β-ray measurement method, etc. Each method has its own advantages and disadvantages: Gravimetric method is a direct and reliable measurement method. It directly measures the source of mass, time, flow, pressure, etc. National benchmarks and standards: The measurement results of other measurement methods must be calibrated using the gravimetric method, that is, the gravimetric method is the benchmark method for measuring the mass concentration of particulate matter in ambient air, and is the basis for verifying the accuracy of other methods and ensuring the authenticity of the measurement results. 1 Range
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GB/T 39193—2020
Determination of mass concentration of particulate matter in ambient air
Gravimetric method
This standard specifies the method for sampling and weighing particulate matter in ambient air by using filter membranes, including the principle and method, instruments and equipment, the construction and expression of sampling and weighing results, the uncertainty assessment of measurement results, quality control and quality assurance. This standard is applicable to the measurement of mass concentration of particulate matter in ambient air by using filter membrane weighing. 2 Normative references
The following documents are indispensable for the reference of this document. For all references with dates, the version with dates shall apply to this document. For all references without dates, the latest version (including all amendments) shall apply to the technical document. (118S3 Systematic processing and interpretation of data Judgment and processing of outliers in normal samples (reference T8170) Numerical rounding rules and expression and judgment of limit values ​​(/T 26497 Electronic Tianban
JJF10591 Evaluation and expression of measurement uncertainty 3 Terms and definitions
The following terms and definitions apply to this document
Particulate matter
particulate matter; PM
Particulate matter in ambient air:
Particulate matter mass concentration
Particulate matter mass per unit volume of air: 3.3
Working point flow
nominal flw ralc
The sampler maintains a constant sampling flow rate under working environment conditions. 4 Principles and methods
The ambient air is extracted at a constant actual flow rate. The particulate matter in the air is retained on the filter membrane. The mass difference of the filter membrane before and after sampling and the volume of air extracted are used to calculate the mass concentration of particulate matter in the ambient air. 5 Instruments and equipment
5.1 Sampler
The sampler should only have the functions of constant flow sampling, timing, and positive temperature measurement, and should report the particulate matter concentration under standard conditions. GB/T 39193—2020
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degrees, the sampler shall record the sampling volume under standard conditions, or call out the measurement data recorded by the sampler to obtain the sampling volume under standard conditions.
5.2 Filter membrane
The sampling port can be made of Naphtha membrane, quartz membrane, inorganic filter membrane or ethylene vinyl chloride, polypropylene, and organic filter membrane. The retention efficiency of the filter membrane for 0.3mrm particles is not less than 99%. 5.3 Standard flow meter
Use the standard flow meter to calibrate the sampler flow meter:
Flow rate: range 0.8 in/min~-1.4 rn/min; maximum allowable error: 2%; flow rate + range 50 L/min-~800 L/min; maximum allowable error: _2; small flow meter: small + 50 [./min; Maximum allowable error: -2% 5.4 Standard thermometer
Used to measure ambient temperature and calibrate the temperature measuring components of samplers and humidity measuring equipment. Measuring range: 3. -50℃, maximum allowable error ±0.5.
5.5 Standard hygrometer
Used to measure ambient humidity and calibrate the humidity measuring components of constant temperature and constant mixing equipment. Measuring range: 40°C to 60°C. Maximum allowable error: ±2.
5.6 Standard barometer
Used to measure ambient atmospheric pressure and calibrate the atmospheric pressure measuring components of samplers. Measuring range: 50kPa~107 kPa. Maximum allowable error: -u.25 kPa.
5.7 Standard stopwatch
Used to check the timing components of the sampler, graduation value: 0.01s, 5.8 Electronic balance
Used to weigh the filter membrane. The appropriate weighing range and graduation value should be selected according to the sample volume and the mass of the filter membrane. Generally, the sample mass should be 100 times the graduation value: the graduation value should not be less than 0.01g, and the technical performance should comply with the provisions of GB/T26297.
The electronic balance should be placed in an environment with the same temperature and humidity control conditions as the humidity control equipment. 5.9 Constant temperature and humidity equipment
Used to balance the temperature and humidity of the filter membrane before and after the sample, the temperature control range: 15℃~-3℃, the temperature fluctuation: ±1'℃, the relative humidity control range: relative humidity 45※~.5%. 6 Sampling and weighing
6.1 Preparation before sampling
6.1.1 Cleaning of sampler
Keep the sampler clean and working smoothly. The cleaning cycle depends on the ambient air quality and the condition of the sampler. 6.1.2 Air tightness check
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GB/T 39193—2020
Before use, the air tightness of the entire sampling pipeline should be checked regularly. Check according to Appendix A using the low pressure method or flow method: When checking using the low pressure method, the leakage rate should not exceed 0.1 kPa/s; when checking using the flow method, the flow difference should not exceed 1 [./nrin. If the entire test cannot be performed due to technical reasons, the air tightness of each component should be tested separately. 6.1.3 Sample flow inspection and calibration
The actual sample flow of the sampler should be checked regularly with a standard flow meter. The inspection method is in accordance with Appendix 1: The sample flow should be within 15% of the flow at the working point. The flow repeatability (s,) should not exceed 2. For samplers that can display the sample flow, the flow display error (△Q) should not exceed ±5. If the sample flow cannot meet the above conditions, the sampler should be calibrated. 6.1.4 Check the timing error of the sampler
Check the timing error of the sampler with a standard stopwatch regularly. See Table 1 for the requirements of timing error of the sampler
Sampling time
23 h-2: h
6.1.5 Check and calibrate the temperature measurement of the sampler. Maximum allowable error
The temperature indication error of the sampler should be checked regularly with a standard thermometer. The maximum allowable error is 2°C. If the temperature indication error exceeds this range, the sampler should be temperature calibrated. 6.1.6 Check and calibrate the atmospheric pressure measurement of the sampler. The atmospheric pressure indication error of the sampling end should be checked regularly with standard air pressure. The maximum allowable error is 1 kPa. If the indication error exceeds this range, the sampler should be pressure calibrated. 6.1.7 Checking the temperature and humidity control of constant temperature and humidity equipment The temperature and humidity indication errors and the temperature and humidity fluctuation range of the constant temperature and humidity equipment should be checked regularly with a standard hygrometer and a standard hygrometer to ensure that the constant temperature and humidity conditions meet the requirements in 5.9. 6.1.8 Checking the filter membrane
The filter membrane should have a flat edge, no punctures, no pollution, no pinholes or damage. 6.2 Balancing and weighing the filter membrane before sampling
The filter membrane with the "oh-" mark should be balanced in the constant temperature and humidity equipment for at least 24 hours. Record the membrane equilibrium temperature and humidity, weigh the filter membrane every day, record the filtration volume and number. Place the filter membrane under the same equilibrium conditions for at least 11 seconds and weigh it again. The difference in mass between the two weighings of the same filter membrane should not exceed ±40 mg (for samplers with small flow rates or small flow rates) or ±0.1 mg (for samplers with large flow rates). If it exceeds this range, the filter membrane will be discarded, and the average of the two weighing results will be taken as the mass of the filter membrane. GB/T 39193—2020wwW.bzxz.Net
6.3 Sampling operation
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In a clean environment, use tweezers to install the weighed filter membrane into the filter membrane clamp with the side of the filter membrane facing the air inlet direction. Insert the filter membrane clamp into the sampler and set the sampling time and other numbers. Start the sampler for sampling. After the sampling is completed, put the filter membrane into a sealed, separate storage box and record the sampling time, sampling volume, etc. During the transfer and installation of the filter membrane, external contamination should be avoided. After the sampling is completed, if the filter membrane is not balanced and weighed, the filter membrane storage box should be placed in a sealed refrigerated environment. Condensation on the filter membrane should be avoided. The refrigerated storage time should not exceed 4 hours. 6.4 Balance and weigh the filter membrane after sampling
Place the filter membrane in a flat environment consistent with that before sampling, balance for at least 21 hours, record the balance temperature and humidity of the filter membrane: weigh the filter membrane with a flat surface, record the filter membrane mass and humidity.
After the first weighing: Place the filter membrane under the same balance conditions for at least 1 hour, then weigh it again, and calculate the difference between the last two measurement results of the filter membrane. If the difference between the two weighings exceeds 0.4 (for small volume or small flow samplers) or -0.41g (for human flow samplers), repeat the membrane balance and weighing operation until the difference between the last two measurement results meets the above requirements. The average of the last two weighing results is used as the mass of the filter membrane.
7 Calculation and expression of results
7.1 Calculation of results
The mass concentration of particulate matter is calculated according to formula (1):
p_mg - m
Where:
Particle mass concentration. Unit is microgram cubic meter (ug/m): The mass of the filter membrane after sampling, unit is microgram (): The mass of the filter membrane before sampling, unit is microgram (): ——Sampling volume, unit is cubic (m): According to the sampling date, the sampling volume is the actual volume or the volume under standard conditions. 7.2 Result expression
The unit of the particle matter concentration measurement result should generally be g/m or mg/m. The result can be rounded off according to the sampling H. The rounding rules should be derived from the relevant requirements of GE/T8170. 8 Uncertainty assessment of measurement results
8.1 Overview
According to the sampling H and measurement requirements, JJF can be accepted. 1059.1 The uncertainty of the measurement result is not an assessment of the uncertainty. See Appendix C for an example of uncertainty calculation. 8.2 Sources of uncertainty According to formula (1), the sources of uncertainty in the measurement result of the gravimetric method should include the factors affecting the sampling flow rate, sampling time, temperature, atmospheric pressure, membrane balance and weighing. GB/T 39193—2020
When using a sample port with only particle size selection function or other sample screening devices for sampling, especially for particulate matter, the standard uncertainty introduced by the sample screening device should be evaluated separately, and the combined standard uncertainty should be calculated according to formula (2): WVui+u
武中.
Combined standard uncertainty, unit is microgram per cubic meter (II): u—standard uncertainty introduced by gravimetric measurement. Unit is microgram per cubic meter (g/m\); standard uncertainty introduced by the sample screening device. Unit is microgram per cubic meter (g/m) The small uncertainty introduced by the change of sample body composition 8.3 Expanded uncertainty
The expanded uncertainty of the measurement result is calculated according to formula (3). = kf,
Where:
Expanded uncertainty, unit is microgram per cubic meter (r/m): Inclusion factor, Table 2:
Synthetic standard uncertainty, unit is microgram per cubic meter (\/m): 9 Quality control and quality assurance
Instrument equipment management
An instrument equipment management system should be established, and the instruments and equipment used in the operation should be verified, calibrated and maintained according to the prescribed cycle. 9.2 Sampling process quality control
.-(3)
The sampler should be placed and installed in accordance with relevant regulations. The color table samplers installed at the same sampling point should meet the corresponding interval requirements. The exhaust of the sampler does not affect the measurement of particulate matter concentration. When installing the filter membrane, you should wear a special experimental sleeve and use saw-free tweezers. In order to monitor the impact of operations such as membrane installation and transfer on the quality of the filter membrane, standard blank filters should be used for quality control during the same batch of sampling. The standard filter membrane should be balanced and weighed together with the sampling filter membrane before sampling and transported to the sampling site. At the sampling site, it should be placed opposite to the sampling filter membrane for a period of time and transported back to the laboratory for post-sampling balance and weighing. The difference in mass of the standard blank filter membrane before and after sampling should be much smaller than the mass of particulate matter loaded on the sampling filter membrane of the same batch, otherwise the sampling data of the batch will be invalid. During the sampling process, if the sampling time does not meet the requirements due to the malfunction of the sampler or external factors, the sample will be invalid. All factors that affect the effectiveness and representativeness of the sampling process should be recorded in detail and analyzed based on the quality control data. Review: Determine the effectiveness of the sampling process:
9.3 Quality control of weighing process
9.3.1 Quality control of electronic balance =
The electronic balance must be kept powered on for a long time or preheated to stabilize after being powered on: Before weighing, check the accuracy of the electronic balance and adjust it according to the needs.
The electronic balance should be checked for accuracy or with a standard code or quality control material similar to the filter membrane quality. If the results of the check show that the performance of the balance has changed and no longer meets the filter membrane weighing requirements, it should be calibrated immediately. GB/T 39193—2020
9.3.2 Quality control of filter membrane weighing
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The quality of the filter membrane should be guaranteed. The marking should not be directly on the membrane (except for the filter membrane that has been pre-marked before leaving the factory): The filter membrane should be treated to eliminate static electricity before weighing. Use the same electronic balance to weigh the filter membrane before and after sampling. Wear dust-free and anti-static gloves during operation. For filter membrane samples with less sampling, use standard filter membrane to control the influence of environmental conditions on the filter membrane weighing. The standard filter membrane uses the same air filter as the sampling filter membrane: 6.2 Weighing and screening, non-continuous weighing standard filter membranes are used as the original quality of the standard filter membranes: When weighing batches of sample filter membranes, weigh at least one standard filter membrane. If the difference between the weighing result of the standard filter membrane and the original quality exceeds the quality requirements, check whether the weighing environment conditions meet the requirements and weigh the batch of filter membranes again.
9.3.3 Quality control of measurement results
According to the sampling number and measurement requirements, CB/T4883 can be used to judge and eliminate outliers for multiple measurement results at the same sampling point.
A.1 Overview
Appendix A
(Normative Appendix)
Method for checking air tightness of sampler
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GB/T 39193—2020
The air tightness check of the sampling curtain can be carried out by low pressure method or flow method: the flow method has higher uncertainty than the low pressure method, so it is suitable for occasions where low pressure test is not technically possible. It can be checked by measuring the flow difference between the inlet and outlet of the sampler, or the flow difference under different load pressures, or the flow after the sampling port is sealed. If the conditions of the sampler permit, the low pressure method shall be used for inspection first. A.2 Low pressure method
Remove the pressure from the sampler system, close the sampling port of the sampler, and use the built-in independent pump to reduce the pressure in the circuit to 75% of the maximum negative pressure that the sampler can withstand. Reduce by at least 4 kPa. Stop pumping, record the gas pressure: and time t:, keep it for at least 1min, then record the pressure and time t, and calculate the leakage rate of the sampler circuit by formula (A,1), -
Where:
Leakage rate, unit is T-Pa per second (kPa/s): -Gas circuit pressure at the end of the inspection, unit is kilopascals (kPa): Gas circuit pressure at the beginning of the inspection, unit is kilopascals (kPa): The time from the beginning of the inspection to the end of the inspection, unit is seconds (s). 5. Repeat the measurement 3 times. The maximum value is the leakage rate of the sampling curtain, A.3 Flow method
A.3.1 Inlet and outlet flow difference method
...-(A, )
Connect the standard flow meter to the sample inlet, record the sampling flow QF, connect the flow meter to the exhaust port of the sampler, record the exhaust flow βQ. Calculate the flow difference according to formula (A.2).
AQ, - IQn -Q..*
Wu Zhong:
The difference between the flow rate at the inlet and outlet is in liters per minute (1./min): The flow rate at the sampling port is in liters per minute (T./min); the exhaust is in minutes (L/min),
The flow rate at the inlet and outlet is generally not more than 1./minaA.3.2
Flow difference method at different load pressures
Connect the standard flow meter to the sampling port and record the sampling flow Q. Install a leak detection button between the flow meter and the sampling port to record the sampling flow Q. GB/T 39193-2020
Sampling flow Q: Calculate the flow difference according to formula (A.3): Wu Zhong:
AQ:— Q.
△Q, one - different load pressure flow difference, the unit is liter per minute (L/min): 2n
When there is no load, the sampling flow rate is in liters per minute (1./min); when there is a load, the sampling flow rate is in liters per minute (I./min). The flow rate under different load pressures should generally not exceed! I./minA,3.3
Zero flow method
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++++++++( A.3)
Connect the standard flowmeter to the sampler gas line, close the sampling port, and record the sample flow rate (Q::Q) after the flow stabilizes. Generally, it should not exceed 1l./min.
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