How is the portable saturated copper sulfate reference electrode calibrated for cathodic protection testing?

If you want to calibrate the reference electrode then you have to buy the scale calomel electrode for calibration, for experimental calibration, calibration method you can look up detailed information. If the reference electrode is not a problem, you put the reference buried in the measurement around, with a multimeter with one end of the reference, one end of the measurement can be measured out of the voltage value.