Keithley 614 Digital Electrometer

The Model 614 is an electrometer with 10-14 A sensitivity, and an input current less than 60fA at 23°. Voltage sensitivity is 10µV to 20V with an input impedance of greater than 50TO (5x10O. Resistance sensitivity of the Model 614 is from 1O to 2x1011O using the constant current technique.