Patent ID: 8683882
Filing Date: 2014-04-01
Classification: G01N

Abstract:
1. A positioning apparatus for aligning a face of a contact sensor, in contact with a test surface of a test material, normal to the test surface, the positioning apparatus comprising: a plunger housing having at least one bore; a plunger slidably received in the bore of the housing; a spherical bearing in the plunger housing comprising: a support bracket coupled to the lower spherical bearing surface and extending from the plunger housing; and the contact sensor received in the support bracket; wherein the plunger is biased toward the lower spherical bearing portion to bias the lower spherical bearing portion toward a centered position on the upper spherical bearing portion when the positioning apparatus is not in contact with the test surface; and wherein a center of a radius of curvature of the lower spherical bearing surface is located on the face of the contact sensor such that the lower spherical bearing portion is rotatable with respect to the upper spherical portion about the center of the radius of curvature.