Study of the Reactivity of Silver,Copper,Silver-Copper, and Silver-Palladium Alloys used in Telephone Relay Contacts

A study is presented of the contamination of pure silver and copper as well as silver-copper and silver-palladium alloys which are used in telephone relay contacts. The contamination tests have been conducted in mixtures of synthetic air + H2O + H2S, with various H2O and H2S concentrations. The amount of resulting contamination on the samples has been determined mainly by electrochemical reduction. With the help of the Centre National d´Etudes des Télécommunications (CNET), France,it was possible to determine the nature and quantity of the contamination deposited on telephone contacts of various compositions having performed under controlled atmospheres.