Abstract :
This paper deals with the circuits in direct-current potentiometers and details of their construction and use. The elementary circuits are first described, followed by the more elaborate ones necessary for precision potentiometers. Thermo-electric effects and other sources of error and methods of obtaining true zero are considered. Some practical details in the accurate measurement of current and voltage are discussed, as well as the devices used for these purposes. The special form of potentiometer used as a voltage standardizer is described.