Additel ADT 912A [ADT912A-N] Low Pressure Test Pump, 1/4 NPT female, 95% Vacuum to 60 PSI (4 bar) Positive Pressure (Air). The 912A Pneumatic Pressure Test Pump is a hand operated pressure pump designed to generate pressure from95% vacuum to 60 psi (4 bar). A high-quality screw press is designed for fine pressure adjustment, with an adjustmentresolution up to 0.1 Pa (0.001 mbar). The 912A is a very stable low pressure calibrator. It makes use of an isothermalbellows chamber which is designed for reducing the possible effects of environmental temperature change. Mostpumps make use of a check valve (non-returning valve) and are not well insulated which will cause large fluctuationsin pressure with a change in ambient temperature or when the unit is touched. The 912A does not use a check valveand is remarkably stable. Two hand-tight connectors installed on the pump allow easy connecting and disconnectingto the test pump without the need for PTFE tape or wrenches. The 912A is an ideal comparison test pump for lowpressure application.