Patent ID: 7116750
Filing Date: 2006-10-03
Classification: G01N

Abstract:
1. A method for detecting and measuring intermittent regions of a secondary material deposited to a moving substrate, said method comprising: (a) providing an x-ray source; (b) locating said x-ray source on one side of said moving substrate, said x-ray source oriented such that said x-ray source directs a beam of x-ray energy onto said moving substrate; (c) providing an x-ray detector; (d) locating said x-ray detector on a side of said moving substrate opposite from said side that faces said x-ray source, such that said x-ray detector receives an amount of x-ray energy from said x-ray source that is transmitted through said substrate; (e) providing a control system in electronic communication with said x-ray source and said x-ray detector, said control system having a processor and associated software for receiving signals from said x-ray detector as said moving substrate passes thereby; (f) receiving at least one signal from said x-ray detector representative of an amount of x-ray energy transmitted by an area of bare substrate adjacent to a region of secondary material; (g) receiving at least one signal from said x-ray detector representative of an amount of x-ray energy transmitted by an area of said substrate containing said region of secondary material; (h) comparing the value of said signal associated with said area of bare substrate to the value of said signal associated with said area of said substrate containing said secondary material; (i) using said comparison of said signals to determine whether said region contains an acceptable amount of said secondary material; and (j) repeating steps (f)–(i) for subsequent regions of secondary material that pass by said x-ray detector.