Measurement of low- and high-value resistance standards at NPL

The paper describes two methods for the measurement of resistance standards; one for low-valued resistors under heavy-current-carrying conditions, and the other for high-valued resistors. The first is a modification to the Kelvin double bridge, which, by introducing a.c. methods, enables the complete bridge balance to be made quickly and easily. The second describes the precautions that are necessary in the application of simple bridge techniques to the measurement of high-valued resistors in terms of the resistance standards described in another paper by the same authors.