Testing for foreign particles in non-transparent encapsulated housings - voltage applied to contact parts to show up conductive bodies

摘要

The testing is for impurities, foreign particles, in non-transparent housings in which contacts, particularly telephone contacts, have been encapsulated using air sealing. The housing, through the testing device, is vibrated and observation is made as to whether there is current flow between opened contacts to which a voltae has been applied. A high voltage source is applied to the contact springs, with the amplitude of the applied voltage such that arcing would not take place between opened contacts in the absence of foreign particles. A current limiter may be inserted in the circuit to limit the arcing current and its duration.