Absolute pressure transmitters are used in a variety of manufacturing processes to monitor and transmit the pressure of liquids, gases and steam. This information is transmitted as an electrical current which is read by a computer. Calibrating a pressure transmitter is vital to the accuracy of the manufacturing process and should be performed on a scheduled bases. This calibration is accomplished with a specific device designed for this purpose.
Close the isolation valves on both sides of the pressure transmitter and depressurize the line by opening the release valve.
Fasten the pressure calibrator's hose to the NPT pressure port on the pressure transmitter by turning it clockwise until tight.
Attach the black lead, from the pressure calibrator, to the negative (-) test terminal on the pressure sensor. Fasten the red lead to the positive (+) test terminal.
Press the power "ON" button on the pressure calibrator. Open the vent on the pressure calibrator by turning it counterclockwise and press the "Zero" button on the calibrator. Close the vent by turning it clockwise.
Press the "Units" button until the display shows "PSI." Press the "Zero" button, and close the bleed valve. Move the pressure vacuum valve to "+" for positive pressure.
Push the hand pump in and out until the display reads three psi. Press the "Hold" button and write down the psi and mA readings from the display. Repeat this process to record the mA for nine psi and 15 psi.
Compare the psi and mA readings to the pressure sensor transmitter manufacture specifications. If the mA specs are not within the set limits, adjust the pressure transmitter according to the manufacturer's directions.