INSULATION RESISTANCE - Test Voltage (DC V): 250V/500V/1000V - Output Voltage Open Circuit: + 10% - Measuring Ranges (Auto): 0-20/0-200/0-2000M Ohm - Output Current: 1mA DC - Accuracy 0-20M Ohm : +/- (1.5%rdg+5dgt), 0-200M Ohm : +/- (2.5%rdg+3dgt), ...