GB/T 37186-2018Gas analysis—Determination of sulfur dioxide and nitrogen oxides—Ultraviolet differential optical absorption spectroscopy (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

1 Scope

This standard specifies methods for the determination of sulfur dioxide and nitrogen oxides in gases using ultraviolet differential absorption spectroscopy.

This standard applies to the determination of sulfur dioxide and nitrogen oxides in gases such as standard gases, industrial gases and ambient air. Sulfur dioxide determination The range is from 0.2mg/m³ to 5000mg/m³, and the nitric oxide measurement range is from 0.3mg/m³ to 5000mg/m³. The circumference is 2mg/m³~5000mg/m³.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 3723 General rules for sampling safety of industrial chemical products

GB/T 5274.1 Preparation of mixed gases for gas analysis - Part 1

GB/T 14850 Gas Analysis Vocabulary

GB/T 33360 Gas Analysis Technical Guide for Gas Purification of Trace Analysis

Technical requirements and testing methods for HJ76 fixed pollution source flue gas (SO2, NOx, particulate matter) continuous monitoring system

JJF1059.1 Measurement Uncertainty Evaluation and Representation

3 Terms and definitions

The following terms and definitions as defined in GB/T 14850 apply to this document.

4 Principle

The sulfur dioxide and nitrogen oxides in the gas sample have a characteristic absorption spectrum in the ultraviolet region, and the ultraviolet light is sucked by the gas to be tested through the gas chamber.

The absorbed ultraviolet light enters the spectrometer. By processing the spectral information, the fast-changing part of the spectrum is separated and inverted Calculated to obtain the content of sulfur dioxide and nitrogen oxides in the gas to be tested. See Appendix A for the specific working principle.

5 Instrument requirements

5.1 Select the measuring instrument within the measuring range according to the sulfur dioxide and nitrogen oxide content to be tested.

5.2 The detection limit of the instrument should meet the requirements of sulfur dioxide and nitrogen oxides to be tested.

5.3 Within the measuring range of the instrument, there should be a definite functional relationship between the response of the instrument and the content of sulphur dioxide and nitrogen oxides.

5.4 The instrument shall be qualified by metrological verification and within the validity period of the verification.