This International Standard specifies a method for the determination of the mass concentration of sulfur dioxide emitted from combustion facilities and technical processes, and defines the most important performance characteristics.

The method described in this International Standard has been tested for a sulfur dioxide concentration range of 6 mg/m³ to 333 mg/m³ with sampling periods of 30 min. It is applicable to mass concentrations of sulfur dioxide exceeding this range by carrying out an appropriate dilution of the sample solutions prior to the analysis or by using larger volumes of absorption solution, and to sulfur dioxide concentrations below this range by extending the sampling period.

This International Standard is applicable to the analysis of samples containing negligible levels of sulfur trioxide and volatile sulfates (< 5 % of the expected sulfur dioxide concentration), and ammonia (< 5 mg/m³).

All concentrations are based on dry gas at a temperature of 273,2 K and pressure of 101,3 kPa.