1. Scope

1.1

General 1.1.1

This Standard applies to the continuous measurement of the concentrations of (a) oxygen (O2) (see Clause 6.1); (b) carbon dioxide (CO2) (see Clause 6.2); (c) carbon monoxide (CO), (see Clause 6.3); (d) sulphur dioxide (SO2) (see Clause 6.4); and (e) nitrogen oxides (NOx); in a continuously extracted sample of combustion gases from an enclosed gas stream (see Clause 6.5).

Note:

Concentrations referred to in this Standard are based on a temperature of 25?C and an atmospheric pressure of 101.3 kPa and are mass per unit volume unless otherwise stated. All percentage (%) or parts per million (ppm) concentrations are by volume throughout this Standard. Commercially available instrumentation using these principles may be capable of exceeding the concentration limits specified in Clause 1.1.1 (a), (b), and (c).

1.1.2

This Standard describes test procedures and equipment that will permit accurate and reproducible determination of the concentration of oxygen, carbon dioxide, carbon monoxide, sulphur dioxide, and nitrogen oxides in enclosed combustion effluent streams and their mass flowrates.

1.1.3

This Standard is intended for use mainly on conventional fuel-fired equipment both before and after gas cleaning equipment, prior to the emission of the effluent stream into the atmosphere, and for routine combustion process control purposes. It may apply to direct fuel-fired equipment where chemical reactions that can affect the measurements are considered negligi ble or are amenable to calculation.

1.1.4

This Standard may be used as a basis for evaluating alternative measuring techniques for the constituent gases.

However, in accepting alternative methods, tests are required to determine the degree of equivalence.

1.2

Limitations It is recognized that there will be some combustion processes and situations that may limit the application of this Standard. Where such conditions exist, caution and competent technical judgement m ust be exercized, specifically when dealing with any of the following: (a) corrosive or highly reactive components; (b) high vacuum or high pressure; (c) high temperature; (d) wet flue streams; (e) fluctuations in velocity or volumetric flowrate and/or temp erature due to uncontrollable process variations (see Appendix G); or (f) extended operating periods.