FLUORESCENT X-RAY FILM THICKNESS METER

PURPOSE:To allow the monitoring of sample image even during the measurement by providing a film thickness meter, having no mirror between a collimator and a sample, additionally with a frame memory thereby suppressing the spread ing of X-ray beam and the lowering of intensity thereof. CONSTITUTION:When measurement is not carried out, a sample image is inputted to a camera 1. An image signal from the camera 1 is stored in a frame memory 9 through an AD converter 8 and also delivered directly to a display 11. In this regard, a CPU 7 presents an signal from the camera 1 directly on the display 11 through a signal switch 12. When a sample is measured, the switch 12 is turned to deliver an image from the memory 9 to the display 11 and the collimator 5 is shifted onto the optical axis of primary X-ray thus starting measurement. Information stored in the memory 9 is a sample image immediately before starting measurement and since the sample 6 is not shifted intentionally, it can serve as a sample image monitor during measurement.