Respirator compensation of a portable air monitor

A respirator-compensated, portable air-monitor has been devised by modifying a commercially available personal air sampling pump. A switching circuit box, integrated into the sampling pump electrical system and activated by a micro switch mounted within the respirator mask, turns the pump off and a timer on whenever the respirator is worn. Thus, valid measurements of an individual worker's environmental exposures can be made even though that worker uses a respirator at his own discretion.