It is an instrument designed to measure an unknown voltage by comparing it with a known voltage. The known voltage may be supplied by a standard cell or any other known voltage-reference source.
Each Slide wire division is equal to 1/2 millivolt or 500 microvolts.
• Coarse and fine rheostats are provided. Terminals for 2 volts battery, Galvanometer , standard cell are provided on the panel.
• Current is of the order of 125 m A. This potentiometer is supplied with a self standardization circuit built in, which renders standardization dependent on setting of voltage dials