ISO International Standard

ISO 15337:2009 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). ISO 15337:2009 uses the reference conditions of 25 °C and 101,325 kPa; however, reference temperatures of 0 °C and 20 °C are also acceptable.