Remote seal DP Transmitter calibration is a procedure in which we check linearity and response of transmitter.
1. Data sheet,
2. Pressure calibrator,
5. Hart communicator.
Procedure of DP Transmitter Calibration:
1:- Ask panel operator to put the controller in manual mode for control loop and to put it on MOS for ESD loop.
2:- Hook up HART Communicator and verify some parameters by refer to data sheet,Typical parameters are, tag number, PV, LRV and URV.
3:- Isolate the instrument from the process.
4:- If the process is hazardous, please ensure proper flushing is done to remove the entire hazard.
5:- Open vent valve at drip ring and open plug at the top of the drip ring (if available) to release the process pressure.
6:- Drop the both remote seal from flange.
7:- Clean the liquid inside the drip ring.
8:- Hook up a multimeter in series with the signal to the DCS to measure current signal.
9:-In this condition both capillary flange will be atm pressure at same hight.
10:- Multimeter should show 4mA and PV at HART communicator should shows 0 (LRV),If not, do zero adjustment at transmitter using HART Communicator.
11:- Connect pressure calibrator to high side flange (drip ring),Apply pressure depend data sheet span (URV),Multimeter should show 20mA and PV at HART communicator should shows same with URV.If not, do span adjustment at transmitter using HART Communicator.
12:-Verify the linearity by increasing and decreasing the pressure (0%, 25%, 50%, 75%, 100%, 75%, 50%, 25% and 0% of range).
13:- After completion of the job boxup the remote seal.
14:- After completion of the job ask panel operator to put loops back in normal mode or normalize the MOS.