Apparatus for measuring the thickness of a coating

摘要

An apparatus for measuring the thickness of a coating on an elongate strip of material which moves along a predetermined path from a first location to a second location. The apparatus includes a measuring device, at least a portion thereof being mounted on a shuttle for movement parallel with the elongate strip. The shuttle is mounted on a support frame for movement back and forth along the frame. The shuttle is further provided with a target-spotting device. A drive extends between the shuttle and the support frame for reciprocating the shuttle along the frame. The drive is responsive to either an on-target signal or an error signal received from the target-spotting device for driving the shuttle from the first location towards the second location to initially position the target-spotting device in registry with the target when an error signal is being received and to subsequently maintain the target-spotting device in substantial registry with the target when an on-target signal is being received so that the measuring device can be maintained in registry with a measurement site having a specific placement relative to the target.