Abstract

A study has been carried out to compare the results of PM10 determinations using TEOM and gravimetric instruments. Whilst the TEOM instruments have been used by the UK Government for many years to develop a National Air Quality Objective, the European Directive (99/30/EC) Stage 1 limit values for PM10 require a gravimetric method (or an approved equivalent method) to be used. However, there are signicant differences between the two techniques, which have been investigated by co-locating a TEOM PM10 monitor and a gravimetric (Partisol) PM10 sampler at Marylebone Road, London between June 1997 and January 2000. This paper investigates the current practiceof using a single correction factor on TEOM PM10 data when these data are being used to assess the EU Stage 1 limit values for PM10, which should be measured using a gravimetric technique. The ability of the corrected TEOM PM10 values to accurately relect the annual mean and the number of 24 h means above 50gm produced by the co-located Partisol PM10 sampler is used as the test for the suitability of the single correction factor. This study demonstrates that a single correction factor will not reflect the site and season specifcity.