GENERAL. a. The Keithley Model 160 Is a completely solid-state, line operated multimeter with the accuracy and convenience of a digital display. It has seven d-c voltage ranges from 1 millivolt full scale to 1000 volts full scale with 100% overranging on every range except 1000 volts. The Model 160 also measures from 100 nanoamperes full scale to 1 ampere with 100% overranging on each range. The ohms ranges are from 100 ohms full scale to 1000 megohms also with 100% overranging. b. The Keithley Model 163 is a Voltmeter-Only version of the Model 160 Digital Multimeter. It has all the main features of the Model 160 except the ammeter and ohmmeter functions are deleted. c. With the use of Keithley Model 1601 AC/DC Probe, a-c measurements can be made from 0.1 volt to 250 volts rms over a span of 45 Hz to 45 kHz. A probe-mounted switch provides convenient selection of a-c or d-c operation without disconnecting the probe. 1-2. FEATURES, a. Accuracy is ±0.1% *1 digit on any voltage range. b. Input Is protected for +/- 1OOO volts continuous input on 1-volt to 1000 volt ranges. Rated at +/- 300 volts continuous input on 1 millivolt range. c. Zero stability is ±2 microvolts/day after one hour warmup. d. Single KANCE Control is designated in convenient engineering units. e. Circuit low to chassis ground isolation permits safe off-ground measurements up to 500 volts. f. Instrument operates from either 50 or 60 Hz, 117 or 234 volt power.