Extech prc30 multi function process calibrator extech prc30 the extech prc30 calibrator is a precision source and measure for thermocouples 8 types ma mv and v devices applications include lab and field calibration and verification of the operation of sensors thermocouple probes controllers panel meters and testing tools it is also ideal for temperature control troubleshooting process device calibration and simulation for transducers transmitters indicators controllers and reco