Universal calibration standard for surface inspection systems

摘要

A universal calibration standard for surface inspection systems has a plurality of hemispherical pads which simulate the liquid scattering due to particulate contamination. The hemispherical pads scatter light irrespective of angles of illumination and detection and of rotational orientation, and are fabricated using ball-limiting metallurgical techniques. Any number and sizes of pads can be arranged on a substrate and the standard can be repeatedly cleaned, thereby having a long useful life.