A highly stable and accurate mains or battery powered DC V calibrator suitable for applications requiring a precision voltage source of low internal resistance.

It has five ranges up to 10 V with a resolution up to 0.01 μV. The compact and robust design make it easily portable and well suited to laboratory, field and industrial use.

Voltage outputs are set by selecting the range switch and dialling up the desired value on the thumbwheel switch.

Output polarity can be selected using the normal/off/reverse switch. The calibrator output resistance is typically 500 mΩ on the 10 V, 1 V and 0.1 V ranges.

The maximum output current that can be drawn on these ranges is limited to 25 mA maintaining specification. The lower ranges have an output resistance of 1 Ω and will supply current up to 30 mA.

A precision zener diode is used as a reference source that provides an input to a F.E.T. chopper amplifier system operating in a feedback stabilised mode.

The gain value is determined by a set of precision metal film resistors, selected by the 5-decade thumbwheel switch on the front panel.

The output voltage is variable from 0.01 μV to 9.9999 V in 5 ranges.

For complete reliability, the calibrator range switch employs two contacts in parallel for each position in case one contact fails, ensuring the calibrator will still function correctly.