The instrument shows results and test options on a large, clear analogue/digital scale for both practicality and precision. A built-in timer makes both spot tests an PI testing easier to carry out. It is powered by a built-in rechargeable lead-acid battery which can be charged directly from any supply from 95 V to 265 V. A guard terminal allows surface leakage to be removed. Pre-set standard test voltages at 500 V, 1000 V, 2500 V and 5000 V are supplemented with a variable test voltage in 25 V steps. These top of the range units also allow measurement of resistance to 5 T1/2, leakage current to 0,01nA and can display capacitance at the end of a test to 10 μF.