Calibration plays an important role in measurement. Instrument operating over and over cause drift in reading cause faulty data report. To overcome such issue calibration is essential. There are interval defined by manufacturer by which time to do calibration is essential.
In this article we will discuss about step of calibration for Analog DP Transmitter.
Let consider below figure for setup.
Follow below step for successful calibration :
1. Make the connections as shown in the figure.
2. Keep low pressure (LP) side of differential pressure transmitter open to atmosphere (For compensation).
3. Use any type of calibrator to set required LRV pressure.
4. By adjusting zero screw of transmitter set output to 4 mA.
5. Put calibrator output to required URV pressure.
6. By adjusting span screw of transmitter set output to 20 mA.
7. For checking linearity of instrument set pressure source output to 0%, 25%, 50%, 75% and 100% in both ascending and descending order and read mA accordingly for 4mA, 8mA, 12mA, 16mA and 20 mA respectively.