Abstract

Several instruments, such as the Dust Trak™recently purchased by the Québec Occupational Health and Safety Commission, provide direct and instantaneous readings of aerosol concentrations. This project was undertaken to evaluate the ability of the Dust Trak to measure respirable and non- respirable dusts, its response to dusts different from the ones use for calibration and its response to variations in humidity. The results confirm the suitability of the Dust Trak for use in exploratory studies, for example the identification of local hot spots due to leaks, tracking of aerosol concentrations over time, or rapid estimation of dustiness. The monitor's response appeared unaffected by variations in humidity below a certain threshold. As predicted by theory, it was not possible to apply a single correction factor for all dusts and dust fractions, but the use of correction factors in exploratory studies appears acceptable, as long as professional judgement is exercised in interpreting the results and certain characteristics of the instrument are borne in mind.