Device and method for measuring the thickness of a sheet of plastic film or paper as it advances during a production process

摘要

The device is of the type which includes a beta radiation transmitter (2) and a sensor (3) designed to measure the beta radiation, arranged on either side of the sheet so that they are synchronously displaced along the surface of the material. The sensor is formed by 4 diodes (7,7',7'',7'''), see Fig. 2, arranged in a matrix. Means are provided to calculate the difference between measurements of two adjacent diodes and to calculate the sum of the four diode measurements and to modify the value of the sum as a function of the difference. An Independent Claim is included for a method of measuring the thickness of the material.