Current to pressure (I/P) converters receive an electrical current signal in a range of 4 - 20 mA and provide a corresponding pneumatic signal in a range of 3 - 15 PSI. The I/P converters are used in valve positioner, where a controller sends an electrical signal to I/P converter and the converter sends a corresponding pneumatic signal to valve positioners that control the valve.
Calibration of I/P converter:
Required Apparatus:
- Air Filter Regulator
- I/P Converter
- Master Pressure gauge (For Measurement of I/P Output pressure)
- mA Source (to feed mA to I/P Converter)
Calibration Procedure:
-
First remove the module final assembly from the housing.
-
Position the range jumper in the Hi position for High Range
-
Connect air supply to the input port, which is connected through the air supply regulator.
-
Connect the output signal port with an accurate output indicator.
-
Make sure the port of the output gauge is installed with an output gauge or a threaded plug. A threaded plug is provided for units shipped without output gauges.
-
Apply a 4.0 mA signal (Vm = 1.0 V) and adjust the zero screw to reach the output of 3.0 psi. The output increases with the zero screw rotation in the clockwise direction.
-
Repeat the last two steps to verify and complete the calibration.