The Quadtech / General Radio Model 1863 Megohmmeter can perform guarded three terminal tests to determine insulation resistance, leakage, resistivity, and voltage coefficient, of insulation, capacitors, and material samples with this handy portable line operated instrument. Test voltages available include 50, 100, 200, 250, and 500 VDC with short circuit current limited to 5 mA. Analog resistance readings from 50 kohms to 20 Tohms (2x10E+13) may be made to an accuracy of Tone2%.