Abstract: A pneumatic null balance pressure transducer comprising a valve body having an inlet duct and an outlet duct, an inwardly projecting metallic bellows and a stem-operated pneumatic valve is disclosed. The stem-operated pneumatic valve is mounted in the valve body so as to be in contact with the bellows in a manner such that movement of the bellows moves the stem of the valve. In operation, external pressure, created by the pressure source to be measured, is applied to the cavity defined by the inwardly projecting metallic bellows. This pressure is balanced against internal pressure generated by a suitable gas source. At balance, the valve closes. In its preferred manner of use, the closed valve captures pressure and the captured pressure is read on a suitable pressure gauge.