The Model 3330B Programmable Constant Current- Constant Voltage Calibrator is a dc calibration instrument which produces output currents from 0 to 111,11110 milli- amperes and output voltages from Oto 1111.1110 volts dc. Output current selection is provided in three ranges and is accurate to within 0.006% of the selected range. Output voltage selection is also available in three ranges with accuracies as stated in paragraph 1*6. Over current and voltage protection features are also provided, thus preventing harm from occuring to devices being tested with this instrument. Front panel indicators provide visual indication of the output current or voltage and the operating modes of the instrument, in-line decade dials and a panel meter indicate the magnitude of the selected output. Indicator lamps provide visual indication of the various operating modes. Systems capability is enhanced by remote control of most operating features. Remote operation is possible through the rear panel Remote connector using either contact closures or DTL/TTL logic. Programming coding requirements are binary 8*4-2-1. The instrument is completely solid-state in design, and module plug-in construction is used for ease in maintenance. The instrument is designed for bench*top use or installation in a 19-inch electronic equipment rack. The chassis is also drilled to accept rack mounting slides.