Abstract: A dual function pressure transducer capable of providing an instantaneous pressure reading, and also of indicating when a sensed pressure crosses a predetermined selectable threshold level. A mechanical pressure sensing device causes an electrical contact member to wipe against a resistance element in response to changes in the sensed pressure, the element and contact being connected in a first electric circuit that provides a pressure readout determined by the location of the contact along the element. The contact is carried by a switch-arm that cooperates with an adjustable switch-pole means to switch a second circuit between first and second modes when the contact crosses a particular point along its path, the location of which is determined by the switch-pole setting.