1-2. The Fluke Model 341Ä and Model 343A' DC Voltage Calibrators provide dc voltages of 0 to 1100 volts in three ranges. Voltages are selected by eleven-position decade switches, which provide in-line, digital readout of the instrument output voltage. The Model 341A employs six-dial readout» with 1 ppm resolution, and the Model 343A employs seven-dial readout, with 0.1 ppm resolution. 1-3. A controlled current limiter, a fixed current limiter, and an electronic crowbar circuit provide protection against instrument malfunction and operator error. Output current or voltage, depending on function desired, are continuously monitored by a front panel meter. 1-4. The instruments are designed for rack-mount installation, using the mounting brackets supplied, and are equipped with resilient feet and tilt-down bail for field or bench use.