Development of a Portable, Fast Response Tracer Analysis System for Concentration Fluctuation Measurements. Phase 1

Concentration fluctuation field experiments performed to date have lacked data pertaining to very short-term changes in tracer concentration. This type of information is critical when a dispersing plume contains toxic or flammable compounds. Therefore, a device capable of very fast response (5 to 10 Hz), measuring the tracer material with high sensitivity, portability, and ease of use is desired. The initial design concept of the tracer analyzer involved sampling by venturi aspiration and measurement by electron-capture detector. After considerable testing and replacement of components, it was determined that the venturi system was not feasible for measuring SF6 in air. A new tracer analyzer design was described, in which an oxygen-removal system is incorporated in a field-portable unit. The concept of the new design has been proven in commercial fast-response SF6 analyzers.