THE APPLICATION OF A VALIDATION PROTOCOL TO A COLORIMETRIC DIFFUSIVE SAMPLER

A validation protocol has been developed by the Comité Européen de Normalisation (CEN) in order to provide a standard evaluation procedure for the many new and existing diffusive sampling systems available for determination of gases or vapours in workplace atmospheres. This study reports the application of that protocol to a commercially available colorimetric diffusive sampling device for acetone. The chosen sampling system was subjected to a series of standard experiments outlined in the CEN protocol to determine the effects of face velocity, exposure time, pollutant concentration, air temperature and relative humidity on sampler performance. Additional non-standard experiments were also carried out to determine the effects of periods of zero pollutant concentration during sampling. The results of both standard and non-standard experiments have been used to calculate figures for the bias of the sampling method and its overall relative uncertainty. Overall, it was concluded that, with some modifications, the CEN protocol can be successfully applied to validating this type of colorimetric diffusive sampling device.