Patent ID: 6664782
Filing Date: 2003-12-16
Classification: G01B,G01D,G01N

Abstract:
A method for measuring a gap between a proximity probe and a conductive target material, said method including the steps of:providing a network of components including a first electrical component, an extension cable component and a proximity probe component respectively serially connected, and locating the proximity probe adjacent a conductive target material; driving a dynamic current through the serially connected electrical components for impressing a first analog voltage across the network and a second analog voltage across the serial connection of the extension cable component and the proximity probe component; sampling and digitizing the first analog voltage impressed across said network to obtain a first digitized voltage value; sampling and digitizing a second analog voltage impressed across the serial connection of the extension cable component and the proximity probe component to obtain a second digitized voltage value; digitally convolving the first digitized voltage value and the second digitized voltage value into a first complex number and a second complex number respectively; calculating a voltage ratio of the second complex number to a difference between the first complex number and the second complex number; processing the voltage ratio into a gap value correlative to a gap between the proximity probe and the conductive target material.