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Delivery: <= 4 days. True-PDF full-copy in English will be manually translated and delivered via email. HJ 1240-2021: Stationary source emission - Determination of gaseous pollutants (SO2, NO, NO2, CO, CO2) - Portable Fourier transform infrared spectroscopy method Status: Valid
Basic dataStandard ID: HJ 1240-2021 (HJ1240-2021)Description (Translated English): Stationary source emission - Determination of gaseous pollutants (SO2, NO, NO2, CO, CO2) - Portable Fourier transform infrared spectroscopy method Sector / Industry: Environmental Protection Industry Standard Word Count Estimation: 15,171 Issuing agency(ies): Ministry of Ecology and Environment HJ 1240-2021: Stationary source emission - Determination of gaseous pollutants (SO2, NO, NO2, CO, CO2) - Portable Fourier transform infrared spectroscopy method---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. (Stationary pollution source waste gas Determination of gaseous pollutants (SO2, NO, NO2, CO, CO2) Portable Fourier transform infrared spectroscopy) National Ecological Environment Standard of the People's Republic of China Fixed pollution source exhaust gaseous pollutants (SO2, NO, NO2, CO, CO2) Determination Portable Fourier Transform Transform Infrared Spectroscopy Stationary source emission-Determination of gaseous pollutants (SO2, NO, NO2, CO, CO2)-Portable Fourier transform infrared spectroscopy method This electronic version is the official standard text, which is reviewed and typeset by the Environmental Standards Institute of the Ministry of Ecology and Environment. Published on 2021-12-30 2022-06-01 Implementation Released by the Ministry of Ecology and Environment directory Foreword...ii 1 Scope...1 2 Normative references...1 3 Terms and Definitions...1 4 Principles of the method...2 5 Interference and cancellation...2 6 Reagents and materials...2 7 Instruments and equipment...2 8 Samples...3 9 Analysis steps...3 10 Result calculation and representation...4 11 Accuracy...5 12 Quality Assurance and Quality Control...5 13 Precautions...6 Appendix A (Informative) Method Accuracy...7 Appendix B (informative appendix) Instrument performance audit results before and after measurement...9 Determination of gaseous pollutants (SO2, NO, NO2, CO, CO2) in waste gas from stationary pollution sources Portable Fourier Transform Infrared Spectroscopy 1 Scope of applicationThis standard specifies a portable Fourier transformer for the determination of gaseous pollutants (SO2, NO, NO2, CO, CO2) in waste gas from stationary pollution sources. Switch to infrared spectroscopy. This standard is applicable to the determination of gaseous pollutants (SO2, NO, NO2, CO, CO2) in waste gas from stationary pollution sources. The detection limits of SO2, NO, CO are all 1 mg/m 3.The lower limit of determination is 4 mg/m3; the detection limit of NO2 is 3 mg/m 3, The lower limit of determination is 12 mg/m3; the method detection limit for CO2 is 1 g/m 3.The lower limit of determination is 4 g/m3.2 Normative referencesThis standard refers to the following documents or clauses thereof. For dated references, only the dated version applies to this standard. For undated references, the latest edition (including all amendments) applies to this standard. GB/T 16157 Determination of particulate matter in exhaust gas from stationary pollution sources and sampling methods for gaseous pollutants HJ 75 Technical Specification for Continuous Monitoring of Flue Gas (SO2, NOx, Particulate Matter) Emissions from Stationary Pollution Sources HJ/T 373 Technical Specifications for Quality Assurance and Quality Control of Stationary Pollution Source Monitoring (Trial) HJ/T 397 Technical Specification for Stationary Source Waste Gas Monitoring HJ 1011 Technical requirements and testing for portable Fourier transform infrared monitors for volatile organic compounds in ambient air and waste gas method3 Terms and DefinitionsThe following terms and definitions apply to this standard. 3.1 Calibration span calibration span The standard gas concentration value for calibration (represented by CS below) should be less than or equal to the highest concentration point corresponding to the standard spectrum in the analyzer's memory. 3.2 error of indication The absolute error or relative error between the measurement result of the standard gas directly introduced into the analyzer and the reference concentration value of the standard gas. 3.3 systematic error The standard gas is directly introduced into the analyzer (direct measurement mode) and the measurement results obtained by the standard gas are introduced into the analyzer through the sampling tube (system The absolute error or the percentage of the absolute error and the calibration range between the measurement results obtained in the measurement mode). 3.4 zero drift Before and after the measurement, the difference between the measurement results of the analyzer for the same zero point gas and the percentage of the calibration range. 3.5 span drift Before and after the measurement, the difference between the measurement results of the standard gas at the same calibration range concentration point by the analyzer and the percentage of the calibration range.4 Principles of the methodWhen infrared light with continuous wavelengths irradiates the molecules of the substance to be tested, the infrared light with the same frequency as the natural vibration of the molecules is absorbed, resulting in wave The number is the abscissa and the absorbance is the ordinate of the infrared absorption spectrum. Different substances absorb infrared light differently, which is a wave with characteristic absorption peaks The numbers are different. Fourier transform infrared spectroscopy is to convert the light emitted by the infrared light source into interference light by a Michelson interferometer, and then use the interference illumination. The gas sample is irradiated to obtain the infrared interferogram, and the infrared absorption spectrum is obtained after Fourier transform processing by the computer system. By comparing gas The infrared absorption spectrum of the sample and the infrared absorption spectrum of the standard substance in the standard spectrum library can be used for qualitative analysis of the sample. Under certain conditions, The characteristic absorption peak intensity of the target compound in the infrared absorption spectrum and its concentration follow the Lambert-Beer law, according to the absorption Peak intensities allow quantitative analysis of target compounds.5 Interference and cancellation5.1 When the infrared absorption spectra of gaseous water and the target compound and different compounds overlap, it is easy to determine the target compound The measurement interferes. In quantitative calculation, the appropriate spectral analysis interval can be selected, or the least squares method or partial least squares-based method can be used. The built-in analysis program of the multiplication algorithm eliminates or overcomes the interference and ensures the accuracy of the measurement results. 5.2 The particulate matter in the gas sample is easy to block the sampling pipeline or contaminate the optical components of the instrument, and a particulate matter filter needs to be installed in the sampling system.6 Reagents and Materials6.1 Commercially available certified standard gases. SO2, NO, NO2, CO, CO2, with N2 as the balance gas, the relative expanded uncertainty Ur≤2% (k=2); or use a gas distribution device that meets the requirements of 6.3 to prepare the required concentration of gas. 6.2 Zero gas. nitrogen (purity ≥99.999%), or clean air that does not interfere with the determination of the target compound. 6.3 Air distribution device. the maximum output flow is ≥5 L/min. The flowmeter should meet. when the flow is less than 50% of the full scale, the maximum allowable flow The error is within ±0.5% of the full scale; when the flow is greater than or equal to 50% of the full scale, the maximum allowable error of the flow should be ±1.0% of the set flow within.7 Instruments and equipment7.1 Fourier Transform Infrared Gas Analysis System 7.1.1 System Composition Fourier transform infrared gas analysis system is generally composed of sampling unit, preprocessing device, analyzer and data processing unit. Among them, the sampling unit includes a sampling tube (including a particulate filter, with heating and heat preservation functions), an air duct, an air pump, etc.; pretreatment The device can choose a constant temperature heating device with a heating temperature of ≥180 °C; the analyzer consists of an infrared light source, an interferometer, a sample chamber and a detector; The data processing unit includes computer, analysis software and reference spectrum. 7.1.2 Performance requirements 7.1.2.1 Indication error. when SO2, NO, NO2 and CO are in the calibration range > 60 μmol/mol, the relative error is within ±5%; When the range is less than or equal to 60 μmol/mol, the absolute error is within ±3 μmol/mol; the relative error of CO2 is within ±5%. 7.1.2.2 System error. when the calibration range of SO2, NO, NO2, and CO is greater than 60 μmol/mol, the relative error is within ±5%; When the range is less than or equal to 60 μmol/mol, the absolute error is within ±3 μmol/mol; the relative error of CO2 is within ±5%. 7.1.2.3 Zero drift. within ±3%. 7.1.2.4 Range drift. within ±3%. 7.1.2.5 Analyzer. the wavenumber range should include at least 900 cm-1 to 4000 cm-1; the total optical path length should meet the requirements of each target compound in this standard. The minimum detection limit is required; the spectral resolution should ensure that the target compound in the gas sample can be separated from the infrared absorption peaks of other coexisting substances. 7.1.2.6 The particulate filter and other properties of the instrument shall meet the technical requirements of HJ 1011 for Type II instruments. Airway and preconditioning The material should be high temperature resistant, anti-corrosion and non-adsorbing, non-reacting with the target compound. 7.2 Standard gas cylinders Equipped with adjustable pressure reducing valve, adjustable rotameter and air pipe made of polytetrafluoroethylene, the material of each component should avoid compounding with the target Physical adsorption or chemical reaction occurs.8 samplesAccording to the relevant provisions of GB/T 16157, HJ 75, HJ/T 373, HJ/T 397, determine the sampling location, sampling point and sampling frequency, Collect samples.9 Analysis steps9.1 General requirements On-site measurement of portable Fourier transform infrared spectroscopy includes steps such as instrument debugging and calibration, sample measurement and so on. 9.2 Instrument debugging Connect the analyzer, sampling tube, airway, pretreatment device and other parts according to the instrument instruction manual, turn on the instrument, and connect the sampling unit, After the pretreatment device and the analyzer have reached the working state specified in the instrument manual, the system shall be air-tight in accordance with the provisions of GB/T 16157. sex check. If the inspection fails, it should be checked for leaks and maintained until the inspection is qualified. 9.3 Calibration 9.3.1 Zero check After the instrument runs stably, introduce the zero-point gas into the analyzer to fully purge the sample chamber, and follow the instructions specified in the instrument manual. Steps to perform a zero check. 9.3.2 Span Calibration Introduce the standard gas of the target compound to be measured into the analyzer at the flow rate specified by the instrument for measurement. If the indication error meets the requirements in 7.1.2.1 If required, the analyzer is available; otherwise, it is necessary to perform span calibration according to the steps specified in the instrument manual. 9.4 Sample determination 9.4.1 Place the front end of the sampling pipe in the exhaust cylinder and as close to the center as possible, and seal the gap around the sampling hole tightly to make it airtight. 9.4.2 Start the air pump, take samples at the sampling flow specified by the instrument, and save the measurement data in minutes after the instrument indication is stable. The measurement was continued for 5 min to 15 min, and the average value was taken as the value of one measurement. 9.4.3 After the measurement of the sample at the same point, clean the analysis system with zero point gas, so that the indication value of the instrument returns to the vicinity of the zero point and remains stable. 9.4.4 Before shutting down, clean the analysis system with zero-point gas, so that the instrument's indication value returns to the vicinity of zero-point and remains stable, and then shuts down the air pump first. Then turn off the analyzer and the preprocessing device, and finally disconnect all parts of the analysis system to end the measurement. 10 Result calculation and presentation 10.1 Result calculation The determination results of the target compounds are expressed as the mass concentration of the dry exhaust gas under the standard state (273 K, 101.325 kPa). in, The NOx concentration is calculated as NO2.The formula for calculating the mass concentration of each target compound is. a) When the instrument indication is expressed in mole fraction (μmol/mol, CO2 is %), SO2, CO and CO2 are converted according to formula (1) is the mass concentration ρ (mg/m3, CO2 is g/m) of the dry base exhaust gas in the standard state 3). SW 22.4 1 xf (1) In the formula. ρ--mass concentration of target compound, mg/m3 (CO2 is g/m 3); M -- the molar mass of the target compound, g/mol; 22.4 -- molar volume of gaseous molecules in standard state, L/mol; x--molar fraction of target compound in wet-base exhaust gas, μmol/mol (CO2 is %); sw --the volume fraction of moisture in the exhaust gas, %; f--unit conversion factor, it is 1 when calculating the mass concentration of SO2 and CO, and 10 when calculating the mass concentration of CO2. b) When the indicated value of the instrument is expressed in mole fraction (μmol/mol), NOx is converted into dry exhaust gas in standard state according to formula (2) The mass concentration ρ of NOx (mg/m3). 2X SW NO NO NO 2.05 xx (2) In the formula. ρ NOX --NOx mass concentration, mg/m 3; 2.05 -- The conversion factor of the NOx mole fraction calculated as NO2 to the dry basis exhaust gas mass concentration under the standard state, g/L; NOx --The mole fraction of NO in the wet base exhaust gas, μmol/mol; 2NOx --The mole fraction of NO2 in the wet base exhaust gas, μmol/mol; sw --The volume fraction of moisture in the exhaust gas, %. c) When the indication value of the instrument is in mass concentration (mg/m3, CO2 is g/m 3) When expressed, SO2, CO and CO2 are converted according to formula (3) Change to the mass concentration ρ (mg/m3, CO2 is g/m) of the dry base exhaust gas in the standard state 3). SW (3) In the formula. ρ--mass concentration of target compound, mg/m3 (CO2 is g/m 3); ρ'--mass concentration of target compound in wet base exhaust gas, mg/m3 (CO2 is g/m 3); sw --The volume fraction of moisture in the exhaust gas, %. d) When the indicated value of the instrument is expressed in terms of mass concentration (mg/m3), NOx is converted into the dry base exhaust gas in the standard state according to formula (4). Mass concentration ρ NOx (mg/m3). 2X SW NO NO NO 1.53 (4) In the formula. ρ NOX --NOx mass concentration, mg/m 3; 1.53 --Conversion coefficient of mass concentration of NO and NO2; NO --The mass concentration of NO in the wet base exhaust gas, mg/m 3; 2NO --The mass concentration of NO2 in the wet base exhaust gas, mg/m 3; sw --The volume fraction of moisture in the exhaust gas, %. 10.2 Result representation When the concentration of SO2, NO, NO2, and CO results in < 100 mg/m 3, reserved to the integer; when the concentration of SO2, NO, NO2, CO When the result is ≥100 mg/m3, keep 3 significant figures. When the concentration of CO2 results in < 10.0 g/m 3 hours, keep to 1 decimal place; when CO2 When the concentration result of ≥10.0 g/m3, keep 3 significant figures. When the concentration of NO2 is higher than the detection limit of the method and lower than the lower limit of the determination, it should be Participate in the calculation of NOx concentration results. 11 Accuracy 11.1 Precision Six laboratories have unified certified standard gas samples containing SO2, NO, NO2, CO, and CO2 at four concentration levels. and the actual gas samples containing SO2, NO, NO2, CO, CO2 were measured 6 times repeatedly, the relative intra-laboratory and inter-laboratory See Appendix A for standard deviations, as well as repeatability and reproducibility limits. 11.2 Correctness Six laboratories have unified certified standard gas samples containing SO2, NO, NO2, CO, and CO2 at four concentration levels. Six replicate determinations were made, and the relative error and the final value of the relative error are shown in Appendix A. 12 Quality Assurance and Quality Control 12.1 Before sample measurement, measure the zero gas and standard gas, and calculate the indication error and system error, which should meet the requirements of 7.1.2.1 and 7.1.2.2 Otherwise, the cause should be found and the corresponding calibration, maintenance or repair should be carried out until the requirements are met before the sample measurement can be carried out. 12.2 After all samples are measured, measure the zero point gas and standard gas again, and calculate the indication error and system error, if 7.1.2.1 and 7.1.2.2 are satisfied If the requirements are met, the sample determination result can be determined to be valid; otherwise, the sample determination result is determined to be invalid. Note. The whole system indication error check including sampling pipe, air pipe, pretreatment device and analyzer can be used to replace the indication error of the analyzer and the system error In case of poor inspection, the inspection results shall meet the requirements of 7.1.2.1. 12.3 The measurement result of the sample should be between 20% and 100% of the calibrated range of the analyzer, otherwise the range should be re-selected and the standard gas should be used for testing. Perform calibration. If the sample determination result is less than the lower limit of this method, it is not restricted by this article. 12.4 Calibration and Period Verification. Check the zero drift and span drift at least once every six months. For instruments that have not been used for more than half a year, The zero drift and span drift should be checked before the next use, and the inspection results should meet the requirements of 7.1.2.3 and 7.1.2.4, otherwise, the Maintenance or repair of analytical systems from time to time. When the frequency of use of the instrument is high, the inspection period should be appropriately shortened and the number of inspections should be increased. Perform moisture inspection on the analyzer at least once a year, or increase the number of inspections appropriately according to the frequency of use of the instrument, and according to the inspection results Moisture calibration is performed in due course. Note. The measurement time of the zero drift and span drift checks shall be kept for at least 1 h. 12.5 When the important parts of the instrument are repaired or replaced, the measurement calibration and moisture calibration should be performed again, and the analysis system should be checked before use. Check the performance indicators to meet the performance requirements of 7.1.2. 13 Notes 13.1 During the use of the instrument, the light source intensity of the analyzer, the performance of the interferogram, and the temperature of the sample chamber should be guaranteed to be stable. Use it under the ambient temperature and humidity conditions specified in the manual of the device. 13.2 If it is found that......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of HJ 1240-2021_English be delivered?Answer: Upon your order, we will start to translate HJ 1240-2021_English as soon as possible, and keep you informed of the progress. 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