An Absolute Determination of Resistance by Campbell`s Method
G H Rayner · Metrologia · 1967
A determination of the NPL unit of resistance in terms of the fundamental units of length and time has been made. It was based on a new, more accurate primary mutual inductor used with an improved Campbell bridge. Measurements in 1963 and 1964, agreed to 0.5 × 10 -6 ; their mean value for the unit that is maintained by the NPL reference resistors is 1 - 3.7 × 10 -6 ohm with a probable error of 2 × 10 -6 ohm.