This test: - is intended to provide accelerated means to assess the effects of the tarnishing of silver and silver alloys used for contacts and connections; - is particularly suitable for giving information on a comparative basis; - is not suitable as a general corrosion test, i.e. it may not predict the behaviour of contacts and connections in industrial atmospheres. The object of this test is: 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 solderless connections made of the same material as in item a) with regard to their tightness or effectiveness. In all tests, the major criterion of performance will be the change in contact resistance caused by exposure to the test atmosphere containing hydrogen sulphide.