Provides an accelerated means of assessing the effect of tarnishing on silver and silver alloys used for contacts and connections. Is particularly suitable for comparative information, but not as a general corrosion test, i.e. it may not predict the behaviour of contacts and connections in industrial atmospheres. The objects are: a) to determine the influence of atmospheres containing hydrogen sulphide on the contact properties of contacts made of silver or silver alloy, silver protected with another layer, other metals covered with silver or silver alloy; b) to check wrapped or crimped connections made of the same materials with regard to tightness or effectiveness. The criterion of performance is the change in contact resistance caused by exposure to the hydrogen-sulphide-containing atmosphere.