Abstract: The present invention relates to a testing device for magnetically testing while uninterruptedly moving along an elongated magnetically permeable object having intermittent supports to one side thereof. The device which is arranged to close around the test the object from all sides other than at the supports and to open at and clear past the supports while continuing to move, comprises first and second housing sections hingedly connected to one another with the first housing section being adapted to maintain the device in a testing position relative to the object and the second housing section being moveable relative to the first housing section for opening and closing the device around the object. An actuator is provided for effecting such opening and closing with a control for operation of the actuator without manual assistance at the device.

Abstract: The present invention provides an apparatus for centering an object within a housing. The apparatus comprises first and second spaced apart adjustable jaw arrangements aligned in the housing, an adjustment for adjusting the opening and closing of the jaw arrangements and first and second connecting members for connecting the first and second jaw arrangements respectively to the adjustment in a manner such that a single adjustment provides substantially simultaneous and corresponding adjustment of each of the first and second jaw arrangements.

Abstract: The present invention relates to a method and apparatus for non-destructive comparative investigation of physical characteristics affecting the reluctance of different parts of a body having magnetic permeability. In accordance with the present invention a first saturating magnetic flux is induced in the body or a part thereof giving rise to a flux distribution pattern determined by the reluctance of the body or part thereof which in turn is determined by the physical character of the body or body part. A second magnetic flux is also induced generally opposing the first magnetic flux in a selected region of the flux distribution pattern, outside of the body or body part while maintaining substantial first flux saturation of the body or body part such that any resultant magnetic flux in that region is at a readily measureable flux level.