Electrical Contact Resistance Between Flat Metal Surfaces

摘要

Low-voltage d-c contact resistance, similar to that in seams and door closures for electromagnetically shielded rooms, was measured between flat specimens of metal with overlap areas between 1 and 20 sq mm; also, some rf impedance measurements were made. Contact resistance and reactance is plotted against normal force, and the results are compared with theory. It was found that salt-air exposure of metals electrolytically plated with zinc, cadmium, or chromium produced surface films which could not be penetrated by normal pressures up to 500 grams/sq mm and wiping distances to 1 mm. A sulfur-dioxide atmosphere had negligible effect on the contact resistance of most specimens. (Author)