The testing of fine wires for telecommunication apparatus

Existing acceptance and quality tests are discussed. War conditions brought increased inspection and an urgent need to classify quality. Most tests were found to be limited in application, or of doubtful value, owing to the wide scatter of results. Abrasion and electrical breakdown are considered in greater detail and a limited enquiry into the pinhole test for enamelled wire is described. The difficulties of chemical tests by the purchaser on textile coverings make such tests impracticable as a control. There is a need for some new improved tests and for appreciation of the limitations of the existing ones.