Abstract
A self-contained positive pressure air supply respirator unit is described which can be used with all types of continuous flow supplied air facepieces. Air demand for the wearer is supplied from the exposure environment through an air purification package consisting of a DC motor, air mover, rechargeable battery pack, and air purification element. The air mover is a miniature, positive displacement, Roots type blower delivering 4.0 CFM at a total head of 2″ H2O. The air supply package weighs approximately three pounds and can be conveniently worn on a belt harness. Performance tests under moderate work conditions showed leakages of less than 0.10% for the three-hour life of the unit.