HJ 920-2017Ambient air--Emergency monitoring method for inorganic hazardous gas--Portable fourier infrared spectrometer method (English PDF)

Foreword

In order to implement the Law of the People's Republic of China on Environmental Protection and the Law of the People's Republic of China on Prevention and Control of Atmospheric Pollution, this standard is formulated by the portable Fourier infrared method for the protection of human health and the determination of inorganic harmful gases in ambient air.

This standard specifies the determination of ambient air carbon monoxide, nitrogen dioxide, nitrogen monoxide, sulfur dioxide, carbon dioxide, Hydrogen chloride, hydrogen cyanide, hydrogen fluoride, nitrous oxide, ammonia and other 10 kinds of inorganic harmful gas portable Fourier infrared method.

Appendix A and Appendix B of this standard are normative appendices, Appendix C is an informative annex.

This standard is released for the first time.

This standard by the Environmental Protection Department of Environmental Monitoring Division and Science and Technology Standards Division to develop.

This standard was drafted. Zhejiang Provincial Environmental Monitoring Center.

This standard verification unit. Hangzhou Environmental Monitoring Center Station, Ningbo City Environmental Monitoring Center, Fengxian District of Shanghai Environmental Supervisor Station, Shanghai Jiading District Environmental Monitoring Station, Nanhui District, Shanghai Environmental Monitoring Station, Xinchang County, Zhejiang Province Environmental Monitoring Station, Zhejiang Jiangde Jiande City Environmental Monitoring Station, Cixi City, Zhejiang Province Environmental Monitoring Station and Beijing Chengtianyouyou Technology Co., Ltd.

This standard MEP approved on December 28, this standard since April 1, 2018 come into operation.

This standard is interpreted by the MEP.

Ambient Air Inorganic Hazardous Gas Emergency Monitoring Portable Fourier infrared method

1 Scope of application

This standard specifies the portable Fourier infrared method for the determination of inorganic harmful gases in the ambient air.

This standard is qualitative and semi-quantitative method for the ambient air carbon monoxide, nitrogen dioxide, nitrogen monoxide, dioxide Sulfur, carbon dioxide, hydrogen chloride, hydrogen cyanide, hydrogen fluoride, nitrous oxide, ammonia and other inorganic harmful gases on-site emergency monitoring, as well as screening, census and other preliminary investigations. If other inorganic gases can also be verified by this method.

The detection limits and determination of the method in Appendix A.

2 Normative references

This standard references the following documents or the terms. For undated references, the effective version applies to this standard.

HJ 194 Manual Air Quality Monitoring Technical Specifications HJ 589 emergency environmental monitoring technical specifications HJ/T 55 Guidelines for Unorganized Emissions Monitoring of Air Pollutants

3 Method principle

When the molecules to be measured are irradiated with infrared light having a continuously changing wavelength, the specific wavelength of the same specific vibrational frequency as that of the molecule Infrared light is absorbed, the infrared light irradiation molecules with a monochromatic dispersion, according to the wavenumber order, and determine the different wavenumber Absorption intensity, infrared absorption spectrum. By comparing the sample with the infrared spectrum and standard reference library quantitative reference material the spectral peak in the characteristic wave number of the qualitative analysis of the peak; according to the sample peak response to the target value and the standard library of Semi-quantitative analysis of the ratio of peak area response values of the standard substance absorption peak should be carried out.

4 Interference and elimination

4.1 When the air relative humidity is greater than 85%, not suitable for monitoring.

4.2 When the sample contains a large amount of dust, it will pollute the instrument piping and analysis unit, the analysis of the interference, must be mining Install the dust filter (5.2) before the sample tube.

5 Reagents and materials

5.1 Nitrogen. Purity >=99.9%.

5.2 Dust filter. glass fiber material, aperture <= 2 µm.

6 Instruments and equipment

7 Samples

8 Analysis steps

9 Results calculated and expressed

10 Precision and accuracy

The method mainly for carbon monoxide, nitrogen dioxide, nitrogen monoxide, sulfur dioxide, carbon dioxide, hydrogen chloride, hydrogen cyanide, Hydrogen fluoride, nitrous oxide and ammonia for qualitative and semi-quantitative analysis, laboratory and laboratory precision and accuracy points Please see Appendix C for the results of the analysis.

11 Quality Assurance and Quality Control

12 Precautions

12.1 Sampling analysis, to ensure that the instrument's light intensity, the height of the interferogram, the temperature of the sample chamber and other parameters stable Check if the conditions of the environment such as temperature, humidity and dust content meet the requirements.

12.2 If the interference figure of the instrument is found to be relatively low after switching on, apply nitrogen to the detector and the background gas chamber Wash; detector rinse, pay attention to control the nitrogen flow rate.

12.3 Sample collection Before and after the sampler pipelines and sample chamber to clean with nitrogen, in particular, to monitor the concentration of higher or have rot After the erosive gas to be fully cleaned.

12.4 dust filter should be replaced each time to prevent cross-contamination.

12.5 Sample collection process to ensure continuous power supply stability. With battery power, the working time is more than 20 min Above, we must observe the instrument's light intensity, the height of the interference figure and other parameters are normal, in order to prevent the wrong results.