1. Calibration method.
The insulation resistance test of the safety energy meter shunt comprehensive tester is to add a certain DC voltage (generally 200V to 1000V) for testing. When calibrating, firstly, calibrate the accuracy of insulation resistance measurement and secondly calibrate the set voltage accuracy.
The insulation resistance test end of the safety comprehensive tester is directly connected to the insulation resistance box terminal. Set the test voltage (eg: 500V DC voltage) to select different insulation resistance values for testing. The displayed value of the insulation resistance is compared with the standard insulation resistance. Change the test voltage (for example: 1000V DC voltage) to do the same test. The calibration method of voltage accuracy is the same as that of high voltage output accuracy, so I will not repeat it.
2. Matters needing attention
When the weather is humid, the AC variable frequency power supply has a larger error in calibrating the insulation resistance (above 1GΩ) of higher resistance. The insulation resistance box should be energized and heated to dehumidify to improve the measurement accuracy.