scope:

In the case of permanent connections, the force is very great and will usually cause permanent deformation of the metals and it is possible that a form of local welding takes place. Such connections are not intended to be made and broken during their lifetime. Examples of permanent connections are crimp and wrap joints. With temporary connections, the force holding the metals in contact is by comparison light and they are of course designed to be made and broken possibly very many times during their lifetime. Examples of temporary connections are: connectors, switches and relays. In temporary connections the areas of metal which make contact with each other are in some cases referred to as contacts. The test has been devised to assess the consequence of tarnishing of silver and some of its alloys. It has been largely validated by laboratory and field tests on silver, though limited tests have also been carried out on components with contacts of some silver alloys.