Continuous thickness meter for moving web - has similar frictional drives direct and through web thickness and compares resulting speeds

摘要

The instrument is for the continuous measurement of the thickness of a web of moving material, in which the web is deflected round a freely rotating drum, and a pair of drums are held against opposite ends of a drum dia. so that one is in contact with the surface of the drum itself, and the other in contact with the surface of the web lying against the drum. Pressure between the drums is adjusted to give a slip-free frictional drive between them without being sufficient to compress the web material. Suitable means are provided to measure the differences in rotations of the two driven drums and evaluate the result as a measurement of web thickness.