The Keithley 168 is a verstile autoranging digital multimeter useful for measurement of the ac and dc voltage, ac and dc current and resistance. Voltage measurements can be made from +/- .0001 volt to +/- 1000 volt dc or .0001 volt to 500 volt ac. Current measurments can be made from .0001 milliampere to 1 ampere, ac and dc in two spans. Resistance measurements can be made from 0.1 ohm to 20 megohms in two overlapping spans. Range and polarity is automatically selected. In addition to the display of digits, the 168 indicates decimal point, function (AC or DC) and measurement unit.