The Keithley Model 6512 Programmable Electrometer is a highly sensitive instrument designed to measure voltage, current, charge, and resistance. The measuring range of the Model 6512 is between 10μV and 200V for voltage measurements, from 0.1fA and 20mA for current measurements, between 0.1Ω and 200GΩ for resistance measurements, and in the range of 10fC and 20nC in the coulombs mode. Very high input impedance and extremely low input offset current allow accurate measurement in situations where many other instruments would have detrimental effects on the circuit being measured. A 4½ -digit display and standard IEEE-488 interface allow easy access to instrument data. Some important Model 6512 features include: • Ideal for low-current measurements—Current resolution of 0.1fA makes the Model 6512 ideal for very lowcurrent measurements. • 4½ -Digit Display—An easy-to-read front panel LED display includes a 4½ -digit mantissa plus a two-digit alpha or numeric exponent. • Auto-ranging—Included for all functions and ranges. • Digital Calibration—The instrument may be digitally calibrated from the front panel or over the IEEE-488 bus. • Zero Correct—A front panel zero correct control allows you to cancel internal voltage offsets, optimizing accuracy. • Baseline Suppression—One-button suppression of a baseline reading is available from the front panel or over the IEEE-488 bus. • One-shot Triggering—A front panel control for triggering one-shot readings from the front panel is included. • Selectable Guarding—A selectable driven cable guard is included to minimize the effects of leakage resistance and stray capacitance. • Standard IEEE-488 Interface—The IEEE-488 interface allows full bus programmable operation of the Model 6512. • Analog Outputs—Both preamp and 2V full-range analog outputs are included on the rear panel. • 100-Point Data Store—An internal buffer that can store up to 100 readings is accessible from either the front panel or over the IEEE-488 bus. • Minimum and maximum data points can be stored and are accessible from the front panel or over the IEEE- 488 bus.