Workpiece material defects e.g. crack, detecting method, involves assigning optical interference filter to light source to select light rays transmitted from source before impingement on workpiece according to type of band pass

摘要

The method involves subjecting a workpiece (2) with a test fluid and radiating the workpiece with short wave light rays (10a, 10, 10c) from a light source (6a). An optical interference filter (12a) is assigned to the source to select the light rays transmitted from the source before the impingement on the workpiece according to the type of the band pass. An optical filter e.g. spectacle lens (16b), is assigned to an eye of an observer to select the light rays emitted from the workpiece before the impingement on the eye according to the type of another band pass. An independent claim is also included for an arrangement for detecting material defects in a workpiece.