Theory and practice in the development of a multisorbent passive dosimeter system.

A new family of passive dosimeters has been developed to allow the use of multiple sorbents and analytical techniques suited to a wide range of sampling situations. The dosimeter hardware has been designed to be reusable with interchangeable sorbent capsule refills to provide low cost per test. Capsules have been designed both for conventional solvent desorption and to be used with a newly developed rapid thermal desorber capable of automation for multiple samples. The development of the system is described together with laboratory tests and results and the effects of environmental parameters.

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.