Calibration Procedure : Differential pressure transmitter

How to calibrate Differential pressure transmitter for capillary type?


Data sheet
Pressure calibrator (std)
Multimeter (std)
Hart communicator


*Ask panel man to put the controller in manual mode for control loop and to put it on MOS for ESD loop.

*Hook up HART Communicator and verify some parameters by refer to data sheet. Typical parameters are, tag number, PV, LRV and URV.
*Isolate the instrument from the process.
WARNING – If the process is hazardous, please unsure proper flushing is done to remove the entire hazard.
*Open vent valve at drip ring and open plug at the top of the drip ring (if available) to release the process pressure
*Clean the liquid inside the drip ring and put back the plug for high side only (if available).
*Expose the low side to atmosphere
*Hook up a multimeter in series with the signal to the DCS to measure current signal.
*In this condition both capillary flange will be atm pressure at difference high
* Multimeter should show 4mA and PV at HART communicator should shows 0 (LRV)
*If not, do zero adjustment at transmitter using HART Communicator
*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
*Verify the linearity by increasing and decreasing the pressure (0%,25%,50%,75%,100%,75%,50%,25% and 0%of range)
*After completion of the job ask panel operator to put loops back in normal mode or normalize the MOS
*Fill the calibration form and file it for future reference.


Capillary flange at same elevation
Example calculation:
Transmitter range = 0-2 kg/cm2
LRV = 0 kg/cm2
URV = 2 kg/cm2.

Related Articles

Leave a Reply

Back to top button

Adblock Detected

We Noticed You're Using an Ad Blocker Hi there! We understand that ads can be annoying, but they help support our website and allow us to continue providing you with high-quality content. Please consider whitelisting our site or disabling your ad blocker while you visit. Your support means a lot to us! Thank you for understanding!