SCHEDULE 9 Reference methods

PART 1 Group A pollutants
	Reference method
Sampling and measurement of benzene	EN 14662: 2005, Parts 1, 2 and 3 ‘Ambient air quality – Standard method for measurement of benzene concentrations’
Analysis of carbon monoxide	EN 14626: 2005 ‘Ambient air quality – Standard method for the measurement of the concentration of carbon monoxide by nondispersive infrared spectroscopy’
Sampling of lead	The same reference method as for PM10
Analysis of lead	ISO 9855: 1993 Ambient air — Determination of the particulate lead content of aerosols collected in filters. Atomic absorption spectroscopy method
Analysis of nitrogen dioxide and oxides of nitrogen	ISO 7996: 1985 Ambient air — determination of the mass concentrations of nitrogen oxides — chemiluminescence method
Sampling and measurement of PM10	EN 12341: 1998 “Air Quality – Field Test Procedure to Demonstrate Reference Equivalence of Sampling Methods for the PM10 fraction of particulate matter”. The measurement principle is based on the collection on a filter of the PM10 fraction of ambient particulate matter and the gravimetric mass determination
Analysis of sulphur dioxide	ISO/FDIS 10498 (Standard in draft) Ambient air — determination of sulphur dioxide — ultraviolet fluorescence method