The Model 8200 is an extremely accurate microprocessor-based,remotely programmable, line-powered portable DC voltage/current standard. Transferring NIST reference values to instrumentation and equipment in the laboratory, the QA/QC department and on the production floor is convenient, fast and accurate. Six decade controls allow adjustment of accurate, ultra-stable DC voltage ranges of 100 mV, 10V, and 100V, in steps of 0.1 uV, 10 uV,and 100 uV respectively, with 10 ppm basic accuracy. If an even wider range is called for, a 1 kV option is available. The Model 8200 also provides outputs from 1 uA to 100 mA as a DC current source, with 100 ppm basic accuracy. The 8200 offers microprocessor-assisted Incrematic control, allowing unlimited use of any one decade with full borrow/carry to and from all more significant decades for easier, faster, and more convenient manual operation. Measurements such as A/D linearity and monotonicity can be made at any chosen resolution, using only one knob. For additional convenience, the calibrator output automatically returns to zero whenever a new range or polarity is selected.