Performing temperature transmitter calibration at the site requires careful planning, proper equipment, and adherence to calibration procedures. Here's a general step-by-step guide to perform temperature transmitter calibration:

1. Preparation:

   • Review the instrument manual and calibration procedure provided by the manufacturer.
   • Gather necessary equipment, including a temperature calibrator, reference thermometer, multimeter, insulated wire, and thermocouple compensating cable if applicable.
   • Ensure safety equipment such as gloves, goggles, and appropriate PPE are available.
   • Identify the calibration points and temperature range required for calibration.

2. Setup:

   • Ensure the temperature transmitter is properly installed and connected in the process loop.
   • Disconnect the transmitter from the process to isolate it for calibration.
   • Ensure power to the transmitter is turned off and lockout/tagout procedures are followed to prevent accidental activation.

3. Zero Calibration:

   • Connect the temperature transmitter to the temperature calibrator or reference thermometer.
   • Apply a known temperature (e.g., ice water bath for 0°C) and allow the temperature to stabilize.
   • Adjust the zero calibration of the transmitter until the output matches the expected value at the calibration point.
   • Verify that the transmitter output corresponds correctly to the applied temperature.

4. Span Calibration:

   • Apply a known temperature (e.g., boiling water for 100°C) to the transmitter.
   • Allow the temperature to stabilize and adjust the span calibration of the transmitter until the output matches the expected value at the calibration point.
   • Verify that the transmitter output corresponds correctly to the applied temperature.

5. Intermediate Calibration Points:

   • If required, perform calibration at intermediate temperature points within the transmitter's range.
   • Apply known temperatures and adjust the transmitter output accordingly to match the expected values.
   • Verify calibration accuracy at each intermediate point.

6. Verification:

   • Once calibration is complete, verify the transmitter output at the calibration points using the reference thermometer or calibrator.
   • Ensure that the transmitter accurately reflects the applied temperatures within the specified tolerance.

7. Documentation:

   • Record calibration results, including calibration points, measured temperatures, transmitter outputs, adjustments made, and any observed deviations.
   • Label the transmitter with the calibration date, technician's name, and any relevant information.

8. Reinstallation:

   • Reconnect the temperature transmitter to the process loop and ensure proper reinstallation.
   • Power up the transmitter and verify its operation under normal process conditions.

9. Regular Maintenance:

   • Schedule regular inspections and calibrations of the temperature transmitter to ensure continued accuracy and reliability.
   • Monitor the performance of the transmitter over time and recalibrate as necessary to maintain accurate temperature measurement.

By following these steps and adhering to proper calibration procedures, you can effectively calibrate temperature transmitters at the site to ensure accurate and reliable temperature measurement in your process or application. If you're unsure about any steps or require assistance, consider consulting the transmitter manufacturer or a professional calibration service.