Development of an instrument for the dynamic generation of test gases

Abstract

A test generator for the dynamic generation of test gases was developed. This device utilizes the saturation vapour pressure principle and enables the calibration of sensitive analytical methods (e. g. gas chromatography) with substance concentrations in the range of maximum acceptable concentrations (MAK- resp. TRK-values). The test gases are producible from liquid and solid substances with finite vapour pressure. The test gas concentration can be calculated from instrumental conditions and the vapour pressure of the substance at a known temperature. Beside the possibility of the continuous and automatic calibration of the measuring monitors the test gas generator is a successful instrument to study interference and adsorption processes. The produced gas stream volumina are infinitely variable to be adjusted to the sampling volumina of different sampling systems (e.g. personal pumps for personal-air-sampling). Component concentrations are determined with a standard deviation of less than 2.3%. In recent research programs the test gas generation from benzene, toluene, xylene, methanol, methanal and phenol has been demonstrated. © 1986 Springer-Verlag.