Transient field indicator

摘要

A photographic film is adapted to provide visual record of the occurrence of a transient electrostatic or transient magnetic field by the inclusion of metallic patterns close to the film. The patterns are of a geometry to define gaps at which the fields are concentrated in a manner to interact with the film. The film exhibits a light spot at the gap, when it is developed, if a field of sufficient intensity is present during the test period. The film packet is intended primarily for inclusion in the shipping package for sensitive electronic devices to provide a visual record of exposures during shipment.