Patent Number: 052992527
Section: claims

1. A fluorescent X-ray film thickness measuring apparatus for measuring a film thickness of a sample, said film thickness measuring apparatus comprising: a collimator having an aperture for forming a primary X-ray beam having a beam axis and a rectangular cross section; means connected to said collimator for rotating said collimator around the primary X-ray beam axis to a desired angular position; and means for monitoring a portion of the sample comprising means for overlapping a representation of the sample portion with a representation of the orientation of the rectangular cross section of the formed primary X-ray beam. 2. A fluorescent X-ray film thickness measuring apparatus comprising: an X-ray tube for generating a primary X-ray;  a collimator having a rectangular aperture for forming the primary X-ray into a beam having a beam axis and a rectangular cross section, the rectangular aperture and the rectangular cross section each having a long dimension;  means for holding a sample at a measuring position for irradiation of a portion of the sample by the beam in order to cause fluorescent X-rays to be emitted from the sample portion, the sample portion having a long dimension;  an X-ray detector disposed for detecting the fluorescent X-rays;  a mirror for reflecting an image of the sample at the measuring position;  display means for displaying the image of the sample portion reflected by said mirror;  a collimator drive motor coupled to said collimator for rotating said collimator about the beam axis and for matching the orientation of the long dimension of the aperture with the orientation of the long dimension of the sample portion; and  indicating means for indicating the orientation of the aperture and sending information indicating the orientation to said display means.