Patent ID: 6225814
Filing Date: 2001-05-01
Classification: G01L

Abstract:
Apparatus for measuring contact width between two contacting surfaces including:first and second insulating substrates having spaced facing inner surfaces and outer surfaces, said substrates being adapted to be fitted between said contacting surfaces;a pair of conductive terminals formed on the inner surface of one of said substrates which terminals are spaced by a distance L, where L is greater than a contact width W to be measured;a conductor formed on the inner surface of the other substrate which extends between said terminals over at least a distance greater than the maximum width W to be measured;a resistance path between said conductive terminals having a resistance R0 which is higher than that of said conductor;material in the space between said conductor and said resistance path which material has a high resistance which substantially prevents current flow therethrough between said conductor and resistance path in areas where said contacting surfaces are not in contact and which has a resistance less than R0 between said conductor and resistance path in areas of said contacting surfaces which are in contact; andcircuitry for applying a signal to one of said terminals and for utilizing a differences in current flow between said terminals to determine contact width between said contacting surfaces.