Fluorescent X-ray film thickness gauge for very small areas

摘要

A fluorescent X-ray film thickness gauge has an X-ray source and a collimator for irradiating a sample with X-rays, and a detector for detecting fluorescent X-rays emitted by the sample. The detector has a cylindrical-shaped housing in which is formed a detector opening for receiving therethrough the fluorescent X-rays to be detected. The detector is rotatable or angularly displaceable about its longitudinal axis to adjust the position of the detector opening relative to the sample so as to effectively minimize variations in the intensity of the detected fluorescent X-rays due to variations in the distance between the sample and the detector.