Patent ID: 6727688
Filing Date: 2004-04-27
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 and a proximity probe component serially connected; driving a dynamic current through the serially connected electrical components including the first electrical component and the proximity probe component for impressing a first analog voltage across the network and a second analog voltage cross the proximity probe component; sampling and digitizing the first analog voltage impressed across said serially connected first electrical and probe components to obtain a first digitized voltage value; sampling and digitizing a second voltage impressed across the probe component to obtain a second digitized voltage value; digitally convolving said first digitized voltage and said second digitized voltage into a first complex number and a second complex number respectively; calculating a voltage ratio of said second complex number to a difference between said first complex number and said second complex number; multiplying the voltage ratio by a value of the first electrical component for determining an impedance of the proximity probe; correlating the determined impedance of the proximity probe to a gap between the proximity probe and a conductive target material.