The Type 1863 Megohmmeter indicates directly on the panel meter any resistance from 0.5 to 20,000,000 MO; the Type 1864 (Figure 1-1) indicates resistance from 0.5 to 200,000,000 MO. These ranges are suitable for leakage- resistance measurements of most types of insulation used in electrical machinery, electronic devices and components, etc (Section 4). The voltage applied to the unknown can be 50, 100, 200, 250 or 500 V from the 1863, as selected by the TEST VOLTAGE switch on the front panel. The 1864 has a voltage range from 10 to 1090 V that can be set in 1-V steps from 10 to 109 V, and 10-V steps from 100 to 1090 V by the TEST VOLTAGE switch on the front panel. The 100-volt level is the EIA standard for measurement of composition, film, and wire-wound resistors above 100 kiloohms. The 500-volt level is a standard value in the measurement of the insulation resistance of rotating machinery, transformers, cables, capacitors, appliances, and other electrical equipment. Regulated power supply and charging circuit permit rapid and accurate measurement of the leakage resistance of capacitors. Guard and ground terminals permit measurement of grounded or ungrounded two or three-terminal resistors. A panel warning light indicates when voltage is applied to the test terminals and thus permits connections to be made safely