The ADT 912 Pneumatic Pressure Test Pump is a hand operated pressure pump designed to generate pressure from -14psi (-0.95bar) to 60psi (4bar). A high-quality screw press is designed for fine pressure adjustment, with an adjustment resolution up to 0.01 Pa (0.0001 mbar). The ADT912 is a very stable low pressure calibrator. It makes use of an isothermal bellows chamber which is designed for reducing the possible effects of environmental temperature change. Most of pumps make use of a check valve (non-returning valve) and are not well insulating in wild fluctuations in pressure with a change in ambient temperature or when the unit is touched. The ADT912 does not use a check valve and is remarkably stable. Two hand-tight connectors installed on the pump allow easy connecting and disconnecting to the test pump without the need for PTFE tape or wrenches. The ADT 912 is an ideal comparison test pump for low pressure application.