Abstract
Diffusional (passive) dosimeters are often required for the determination of time-weighted average concentrations of sulfur dioxide under relatively severe workplace conditions. The method developed here combined the use of a diffusional dosimeter and a relatively non-toxic buffered formaldehyde absorbing solution. The dosimeter was found to give reproducible results using two lots of General Electric single-backed dimethyl silicone membranes; sampling times from 1 to 7 hr; sampling temperatures from 25°C to 38°C; and at face velocities from 0–600 ft/min (0–3 m/s). Concentrations as low as 0.05 ppm were determined over a maximum sampling time of 7 hr, yielding a sensitivity better than 0.35 ppm·hr. Fluctuating concentrations from 0.5,1.0 or 2.0 ppm background to 10.0 ppm for 1/2 hr were shown to result in no significant error.