The Temperature Coefficient of Resistance of Copper (Classic Reprint)

Excerpt from The Temperature Coefficient of Resistance of Copper For the resistance measurements the wires were placed in a specially designed oil bath with provisions for efficient stirring of the oil, for heating and cooling, and for temperature regulation. The wire was held between heavy clamps through which the cur rent was introduced. For conductivity determinations the resist ance was measured between knife edges mounted 1 meter apart on the marble base. The Thomson bridge method was used for measuring the resistances, employing a double set of variable ratio coils; an accuracy of 1 in 10 000 Was easily attained. The resist ance of the copper sample was compared with the resistance of a copper standard in the same bath as the test sample. The copper standards were wires carrying soldered potential leads and placed in frames having connections for both current and potential leads. These connections dropped into mercury cups 0n the marble base in the oil bath. The resistances of the copper standards were compared from time to time with manganin resistance standards which were kept in a separate oil bath. The method of comparing the copper samples with a copper standard has the advantage that accurate temperature measurement is unnecessary. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.