This International Standard provides definitions and specifies methods to determine performancecharacteristics of an identified automatic air quality measuring system. Tests are carried out under stable laboratory conditions or field conditions. The automatic measuring system is considered as a black box operated according to specified procedures.This International Standard applies to measuring systems for which the following information is available:. a description of the automatic measuring system providing the result of measurement in the physical unit of the measurand;. operating procedures of the automatic measuring system including, where appropriate,