Automated thickness measurement system

摘要

A method for and system of measuring the thickness of a component dimension of a sample material. Sound waves are coupled for transmission along a component direction of a sample material and also through first and second reference standards to provide first and second reference thicknesses. As the sound wave signal is transmitted, the time for the sound wave signal to traverse the sample thickness and the first and second reference thicknesses is measured. The thickness of the sample is calculated by calculating the velocity of the signal from the traverse times for the first and second reference thicknesses. Preferable, the calculations are made by a computer, and may be repeated over a period of time to calculate a change of thickness as a function of time. The computer may be used to compare the instantaneous thickness of the sample with at least one parameter such as information used to control a process, a predetermined minimum or maximum thickness a predetermined rate of change with respect to a minimum or maximum time, or a predetermined uneven change in thickness between a plurality of sample thicknesses. The sample may in fact comprise a plurality of locations on a tube, and the process may control a tube being subjected to plating process or a tube that is subject to at least potential erosion of its thickness.