DIGITAL SCALE FOR TOMOGRAPHY AND METHOD OF USING SAME

摘要

A test object for measuring the depth of focus of an X-ray exposure. The test object is comprised of a planar surface of X-ray transparent material on which are positioned a coded array of X-ray opaque elements. In use, the test object is angularly inclined to the X-ray field so that the number of coded elements in focus in the resulting X-ray exposure provides a measurement of the depth of focus of the X-ray device.