Instrumentation Knowlege

•  Calibration of Thermocouple type Temperature Transmitter:

Calibration is important and difficult producer. its required Competent Person who have Qualifications, experience and training. And also know about Safety precautions that's necessity.

Following are producer of Calibration of Temperature transmitter thermocouple type.

Equipment's required:

 a) Temperature Transmitter, 

b) 24 VDC power supply 

c) Multimeter digital 

d) Milli volt source {(DPC-725/754 (documenting process calibrator   

Formula for finding Ranges: 

Formula: - For a ‗K‘ type thermocouple: 

mV = °C × 0.0416 

°C = mV ÷ 0.0416 

• Connect the circuit as shown in figure.
•   Put multimeter into ma. 

Range = 0 ~ 200°C 

Formula: - mV = °C × 0.0416 

 temp= 50°C mV = 50 × 0.0416 

= 2.08 mV

•  5 point calibration values

1. Select thermocouple option in process calibrator.
2.   And give different values of temperature in process calibrator and check the mA in multimeter and by adjusting zero and span potentiometer in the transmitter correct the ma values. 
3.  Repeat this procedure.