US Patent 7937849 Concentricity sensor and methods of use and application

A method for measuring concentricity of one cylindrical member arranged in a second cylindrical member includes the steps of inserting a tool in the second cylindrical member, moving a first set of elements carried by the tool into engagement with the inner surface of the bore, establishing a “zero” position for the first set of elements, measuring for each element the distance of movement from the “zero” position of that element to the position where that element engages the inner surface of the bore. The method further entails adjusting the position of first cylindrical member relative to the second member within a tolerance range based on the distances measured from the “zero” positions.