Instrument for calibrating pressure gauges

Abstract

A microprocessor controls pressure transducer testing, calibration, and adjustment. A transducer or unit under test (UUT) receives a fluid pressure signal from a test line, and outputs a corresponding electrical signal. A test pressure is output from a fluid pressure module which is connected to the UUT. A human operator is interrogated by the microprocessor based control unit as to (1) identifying details about the desired pressure UUT to be tested, and (2) the anticipated electrical range to be encountered in reply to an applied test pressure. The microprocessor then sequentially generates electrical output signals which are sent to the test lines to generate the test pressure pulses from a fluid pressure supply. The pressure test pulses are delivered to the UUT. As the UUT receives the sequence of pressure test pulses, the microprocessor records the output electrical signals generated by the UUT, and compares them to an internal reference pressure transducer output. Display of the results occurs with preferably the percent error calculated at each step. Provision for pressure transducer UUT calibration is made by providing the calibration instrument with the ability to issue tonal and visual signals in response to UUT adjustments, thus providing sense and amount of adjustments of the zero point and span range of the transducer under test.