How RTD is Calibrated.

Consider That We Need to Monitor Temperature in Tank. For That We Have Bought a New Resistance Temperature Detector Or RTD.

As You Know RTD Is a Temperature Sensing Device Which Gives Resistance as Output and Whose Resistance Increases with Increase in Temperature. The Output of This RTD May Be or May Not Be Accurate.

To Confirm the Accuracy of The RTD Calibration Is Done. To Perform RTD Calibration Usually Dry Block Calibrator or Temperature Bath Is Used as Calibrator.

RTD Which Is to Be Calibrated Will Be Placed into The Temperature Calibrator.

The Calibrator Maintains a Fixed Temperature Which Is Set by The User and So the Output Resistance of the RTD Changes with Respect to The Temperature of The Calibrator.

Now A Multimeter in Resistance Mode Is Connected Between the Terminals of The RTD to Read the Output Resistance Value of the RTD.

This Output Resistance Value Is Compared with The Standard Resistance Vs Temperature Chart Provided by The Manufacturer to Find the Exact Temperature Detected by the RTD.

The User Now Makes a Record by Entering This Value of Temperature Detected by The RTD and The Temperature Displayed on The Calibrator. This Procedure Is Repeated for Few Other Sets of Temperatures Within the Range for Which the RTD Is Used and The Readings Are Recorded.

If Both the Temperatures Displayed Are Same or Within Acceptable Deviation from The Standard Value.
The RTD Is Considered to Be Accurate.

A Final Document Called Calibration Certificate Is Prepared Which Contains List of Calibration Standards Used for The Calibration. Any Data Resulting from The Calibration, The Calibration Date and Possible Pass or Fail Statement for Each Measurement Results.

This Is how a typical RTD Calibration Is Done

Read more: What is Calibration and How Calibration is done