This document specifies a continuous measurement method for the determination of the concentration of ozone present in ambient air based on the ultraviolet photometric measuring principle. This document describes the performance characteristics, and sets the relevant minimum criteria required to select an appropriate ultraviolet photometric ozone analyser by means of type approval tests. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the Directives data quality requirements and requirements during sampling, calibration and quality assurance.