Improvements in the validity of charcoal tube sampling by the use of a unique low flow true total volume sampling pump.

Standard methods of determining toxic vapor exposures rely heavily on charcoal tube sampling. The validity of results depends critically on accurate determination of the total air volume and avoidance of saturation breakthrough. The difficulty of substantiating sampling validity has stimulated a search for more absolute methods. A novel pump will be described which fulfills the requirement of true total volume measurement and has a flowrate capability down to 1 cc/min. This low flow feature lends itself to a variety of new detection techniques which will be outlined together with a detailed description of the unit's function.