USE “SEARCH” TAB ON the top right side FOR ALL INSTRUMENTATION RELATED TOPICS
1.Obtain necessary Permit to Work.
2.Override the trip if it is connected to any trip system.
3.Open the top cover of the Temperature Transmitter and open all RTD/TC wires.
4.Connect Multi function calibrator to the transmitter in place of RTD/TC wires as shown below
For RTD calibration the connection is as shown below
For thermocouple calibration the connection is as shown below
5.Select Temperature Simulation mode in Multi function calibrator and select RTD/TC type and feed Temperature input to the temperature transmitter.
6.Apply Temperature input 0%, 25%, 50%, 75% and 100% of the temperature range and accordingly check and note down the readings of HART Communicator and current output of transmitter (mA). Repeat the same for decreasing steps.
7.Calculate the error and compare with allowable limit.
8.If the error is within limit then calibration is ok. If calibration is ok then go-to step 13. Otherwise continue step 9.
9.If the error is not within limit then zero and span calibration required through the HART.
10.For zero calibration apply temperature to lower range and wait for stabilization of the reading. Basic Set up – Calibration –Lower range value trim.
11.For Span calibration apply upper range temperature value to the transmitter and wait for stabilization of the reading. Basic Set up – Calibration –Upper range value trim.
12.Repeat Step No. 4 – 7.
13.Ensure the readings at HMI.
14.After completion of the same, restore the RTD/TC connections of transmitter.
15.Ensure the transmitter output corresponds to atmospheric temperature.
16.If temperature is OK, close the cover. Place the RTD/TC back in service. Go to step no. 15.
17.If temperature is not OK, check RTD/TC, if necessary replace old RTD/TC with New one. Go to step no. 15.
18.Inform production department after completion of the job. Normalize the trip override if
Close the Work Permit.
The temperature transmitter calibration check list is as shown below
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