Apparatus for nondestructively determining coating thickness on a metal object and associated method

摘要

Apparatus and an associated method for nondestructively determining the thickness of a coating on a metal surface, such as the interior of a can. An object securing device holds the object being inspected. The inspection device includes a probe. Positioning apparatus is employed to permit insertion of the probe into inspecting relationship which in the case of a can would involve partial insertion of the probe into the can. A first section is inspected and sequentially through relative rotational and/or translational movement of the object being inspected additional portions of the object such as can ends may be inspected. A light beam is caused to impinge upon the section of the object being inspected and returned fluorescent light received by a detector positioned within the probe cooperates with processing means to determine the coating thickness. The system permits accurate determinations of coating thickness even when the metal surface has irregularities. The system may be employed on metal sheet including moving metal sheet. The probe may include mirrors and fiberoptic components. A suitable lens for focusing the returned light and a filter for excluding extraneous returned light from the detector preferably are employed. A container holder is also provided.