CHEMICAL DOSIMETER HAVING A CONSTANT FLOW AIR SAMPLING PUMP

摘要

Abstract of the DisclosureAn improved chemical dosimeter for individual usewhich collects on a filter particles or vapors present in anair stream which is being pumped through the dosimeter at aconstant rate, the improvement is the use ofa variable drive pump that is connected to thefilter and that is driven by an electric motor and iscontrolled by a feed back circuit of an integratorand an amplifier and maintains a constant flow ofair through the dosimeter;the integrator receives a signal from a pressureswitch that detects changes in the flow of the airstream through the dosimeter by a change in apressure drop of the air which is being pumped throughan orifice;the dosimeter is worn by an individual and at thetermination of a period of time, such as a work day, thefilter is removed and the collected contents are analyzed byconventional techniques such as gas chromatography to deter-mine a level of exposure of the individual using thedosimeter.