1 Scope
This International Standard specifies the gas phase titration (GPT) method for the calibration of ambient air ozone (O3) analysers. The method is applicable to the calibration of O3 concentrations in the range 10 µg m−3 (5 nmol mol−1 mole fraction) to 2 000 µg m−3 (1 000 nmol mol−1 mole fraction). This International Standard uses the reference conditions of 25 °C and 101,325 kPa; however, reference temperatures of 0 °C and 20 °C are also acceptable.