Abstract
An optical method has been proposed and its system has been developed for measuring the change in diameter during the production of polyester filament in a manufacturing plant. The principle of the method is based on the application of scattered light on the filament. The sensor head of the system consisted of a semiconductor laser, two silicon-photodiodes as a light receiver, and a cylindrical lens. It was found from a preliminary experiment that (1) the scattered light intensity was not proportional to the diameter but to the cross section of the filament in the range between a few ?Em and a few tens μm, (2) the measurement error for the diameter of the polyester filament was 8 % for a scattered light intensity measurement error of 15 %, and (3) the system could be used in practical applications.
