The Keithley Model 619 is a fully programmable, microprocessor based Electrometer/Multimeter. Its broad measurement range is from 2nA, with 100fA {1013A) resolution on the most sensitive range, to 2A. The Model 619 ohms measurement range is from 2k {0.10 resolution) to 2T. The volts measurement range is from 200mV (1/A/ resolution to 200V. The Model 619 is capable of 0.0005% resolution. It can be interfaced to any programmable measurement system utilizing the IEEE-488 Interface bus. (See Figures 2-1 and 2-2 for front and rear panel detail.) 1.2 FEATURES The Model 619 includes the following features: • Resolution of 41A or 5V4 is standard with the Model 619. Resolution of 3'/2 is available only when programmed through the IEEE-488 bus. • The IEEE-488 Interface option (Model 6193) enables the Model 619 to be incorporated into a measurement system that utilizes programmed control through the IEEE-488 bus. • The modular construction concept allows for future developement of a line of interfaceable products. • Whenever two Model 6194 Electrometer Modules are installed, there are two seperate input channels. Channels A and B measure separately through the READ command and they are separately switched into the A/D Converter. Channel B is an option. • Ratio A/B takes a ratio of the two channels, always dividing A by B. • Difference A-B subtracts the electrometer value of Channel B from Channel A. • A beeper sounds whenever a front panel push-button switch command is given. The beeper is enabled by Switch 1 on the Isolator Board. • The Model 6191 Guarded Adapter, in the guarded switch position, reduces the effect of additional input cable capacitance (see paragraph 2.2).