Abstract
A pyrolyzer and a microcoulomb detector (Mast Ozone Meter) connected in series were evaluated as a direct-reading air-sampling instrument. Among the features of this system is the new method for measuring certain halogenated hydrocarbons in concentrations well below 1 ppm with direct readout capability. The system has been used for in-place testing of charcoal filters with methyl iodide. Application of the system to testing for a variety of halogenated hydrocarbons gave lower limits of detection ranging from 2 ppb for methyl iodide to 900 ppb for tetrachlorodifluoroethane. The system was found to be insensitive to benzyl chloride and to 54% chlorinated diphenyls.