Backscatter apparatus and method for measuring thickness of a continuously moving coated strip of substrate material

摘要

A backscatter measurement device for measuring the thickness of a coating on a strip of substrate material moving from a feed supply to a take up location at a predetermined speed. A measurement wheel is provided on the rim of which are mouted backscatter probes for irradiating and detecting the backscattered radiation from the coated substrate. The coated strip of substrate material is threaded around the outer surface of the rim. The measurement wheel is rotated at a speed such that the tangential speed of a point on the rim equals the speed of the moving strip whereby the probe and an adjacent point on the strip are stationary relative to one another while the point on the strip is adjacent the rim. Thus thickness measurements may be taken without stopping the movement of the coated strip.