[IEEE Electrical Contacts - 1996. Forty-Second IEEE Holm Conference on Electrical Contacts. Joint with the 18th International Conference on Electrical Contacts - Chicago, IL, USA (16-20 Sept. 1996)] Electrical Contacts - 1996. Proceedings of the Forty-Second IEEE Holm Conference on Electrical Contacts. Joint with the 18th International Conference on Electrical Contacts - Characteristics and electric contact behavior of tarnished film covered on silver plated surface formed by indoor air exposure