Indexer Position Check for Disk Measurement System
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
The procedure measures the distance the center of a disk-holding fixture (hereafter "hub") travels from the "home" position to the center of the x-ray beam within an x-ray fluorescence thickness tester. This parameter is important to the translation of coordinate systems for disk alignment. The problem arises because the hub cannot travel fully under the beam due to the tester's mechanical limitations. This method is essentially that of measuring the distance from "home" to a known point on a special disk (Fig. 1) by the following procedure, then adding the radius of that point to get to the center of the hub. xhome-to-center = xhome-to-point + xpoint-to-center This is down at two places for better accuracy.