This International Standard specifies an ultraviolet (UV) photometric method for the determination of ozone in
ambient air. It is applicable to the determination of ozone concentrations in the range 2 mg/m 3 (volume fraction of
1 x 10-9) to 2 mg/m 3 (volume fraction of 1 x 10-6). Furthermore, this International Standard uses the reference
conditions of 25 °C and 101,25 kPa; however, reference temperatures of 0 °C and 20 °C are also acceptable.
For calibration, this International Standard specifies ultraviolet photometry as the primary reference procedure
because of its proven accuracy and specificity to ozone. The use of secondary reference procedures (often called
transfer standards), including non-UV methods, is allowed if they have been previously calibrated by the primary UV
reference procedure (see ISO 6879 for definitions).