Ross Engineering Corporation Hi-Z? High voltage voltmeters are ideal for accurate capacitor voltage tap test point measurements, phasing, energized line indication, and direct HV line voltage measurements. The VM25 models measure low-current high-source impedance voltages in three or more ranges up to 25kV. The VM50 and VM100 models measure up to 50kV and 100kV respectively in four or more ranges. HV inputs are high impedance, ranging from 85 megohm to over 1,000 megohm as required. These meters are partially shielded from stray electric fields and have 125kV, 150kV or 300kV basic pulse tests, among others. All models use large digital or analog instrument scales for accurate voltage measurements. Basic accuracy is ±.5% digital and ±3% analog.