DOSIMETER FOR MONITORING WORKING AREAS

摘要

An improved dosimeter for monitoring working areas in which air, preferably in a relatively large volume, is pumped through the dosimeter at a controlled constant flow and any particles or vapors in the air are collected on a filter, the improvement is the use of A VARIABLE DRIVE PUMP CONNECTED TO THE FILTER AND DRIVEN BY AN ELECTRIC MOTOR AND CONTROLLED BY A FEED BACK CIRCUIT OF AN INTEGRATOR AND AN AMPLIFIER AND THE PUMP MAINTAINS A CONSTANT FLOW OF AIR THROUGH THE DOSIMETER; IN THE OPERATION OF THE DOSIMETER THE INTEGRATOR RECEIVES A SIGNAL FROM A PRESSURE SWITCH THAT DETECTS CHANGES IN THE FLOW OF THE AIR STREAM THROUGH THE DOSIMETER BY A CHANGE IN A PRESSURE DROP OF THE AIR WHICH IS BEING PUMPED THROUGH AN ORIFICE; THE DOSIMETER IS PLACED IN A WORK AREA AND AT THE TERMINATION OF A PERIOD OF TIME, SUCH AS A WORK DAY, THE FILTER IS REMOVED AND THE CONTENTS COLLECTED ARE ANALYZED BY CONVENTIONAL TECHNIQUES SUCH AS GAS CHROMATOGRAPHY TO DETERMINE A LEVEL OF EXPOSURE OF INDIVIDUALS WORKING IN THAT AREA.