Cross conductivity standard for nonferrous metals at NIM

Abstract

A so called "cross conductivity standard" based on a new principle developed from Thompson-Lampard Theorem (1956) has been established at N I M by the end of 1992.The conductivity range of the standard is approximately from 3% IACS to 100% IACS and with an uncertainty about 0 . 0 7 % .By using an AC measuring system and a new method, the unknowns can be calibrated with an uncertainty of (0.1% rx + 0.12% IACS).