How To Calibrate I/P converter

How To Calibrate I/P converter / Calibration Procedure for I/P converter. 

Types of equipment required:-

1. I/P converter,
2.  Milliamp source,
3. Pressure source(20 psi).
4. Master gauge.

The procedure of I/P converter online Calibration:-

1. Remove the I/P from the process.
2. If there is any top cover in I/P remove it.
3. Connect 20-psi supply pressure and connect a milliamp source to the I/P.
4. Set the input signal to 4 mA and check the output pressure on gauge as 3 psi.
5. If the pressure is showing more or less than 3 psi then adjust zero.
6. Turn zero adjustment screw slowly by very small turn to obtain 3-psi pressure. More turning of zero adjustment may damage the I/P converter. Counterclockwise rotation increases the pressure, and clockwise rotation decreases the pressure.
7. Set the input current signal to 20 mA and check the output pressure on gauge as 15 psi.
8. Turn the span adjustment potentiometer very slowly by small turn to obtain 15-psi pressure. More turning of span adjustment may damage the I/P converter.
9. Repeat step 4 to check that the desired low value (4 ma ~ 3 psi) has not changed after adjusting the span. If necessary repeat from steps 3
10. Reconnect the I/P in the process.