Radial Diffusive Sampler for the Determination of 8-Hour Ambient Ozone Concentrations

The 8-hour ozone Radial diffusive sampler was evaluated according to the CEN protocol for the validation of diffusive samplers and to the O3 European Directive. All the parameters regarding the sampler characteristics (blank value, desorption efficiency, storage before and after exposure, sampler integrity) were found to be consistent with the requirements of this protocol apart from the blank value which must be evaluated and subtracted at each sampling. The nominal uptake rate determined in laboratory conditions was 81.5 ± 0.3 cm³.min-1. However, the uptake rate depends on the mass uptake, temperature and on the combination of temperature and humidity while it was found independent of the wind velocity and direction. Based on laboratory experiments, an empirical model has been established. Using this model, the agreement between the radial sampler and the reference methods was improved compared to the radial sampler results using the nominal uptake rate. This improvement was observed with the results of an international intercomparison of diffusive samplers and with the routine measurements at 5 European monitoring stations showing different meteorological and emission conditions. In this study, it was shown that by using the model equation of uptake rate, the data quality objective of 30 % for the expanded uncertainty is easily attained. Therefore, the ozone Radial sampler is an appropriate indicative method for monitoring ambient ozone.

PLAISANCE Hervé;  GERBOLES Michel;  PIECHOCKI Audrey;  DETIMMERMAN F.;  DE SAEGER Emile; 

2007-05-15

ELSEVIER SCI LTD

JRC33565

0269-7491,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC33565,   

10.1016/j.envpol.2006.11.032,