Quality is crafted into every Major Megger insulation tester, with excellent test voltage regulation, direct measurement readout and an external guard terminal to eliminate sur face leakage current from the measurement. Five models are available for general purpose testing which include a low-voltage model. Four of the models feature an analog display having four selectable test voltages of 100, 250, 500 and 1000 Vdc, measuring insulation resistance up to 2000 M ohm, and an ohm range to 5000 ˜. They are designed for the safe testing of motors, generators. cables, switchgear, transfor mers, distribution networks, industrial and domestic installations, components and appliances. The range of insulation test voltages available allows one instrument to be used for a variety of applications. For example, installations and equipment can be tested at 1000 V d.c. when this requirement is specified, also aircraft and tele-communications equipment can be tested at the relatively low 100 V d.c. and 110 V to 120 V a.c. systems can be tested using 250 V d.c. Insulation resistance: 0.1 ohm - 2000 Mohm. Accuracy: +/-1.25 percent of fsd on a 2.8 in (71.1mm) arc length. Nominal test voltages d.c: 100V, 250V, 500V, 1000V. Midscale: 4 Mohm. Short circuit current: 1.9 mA. Resistance range: 0.1 ohm - 5000 ohm.