Ultrasonic wall thickness measurement for plastics components - using oscillating ultrasonic measuring heads supplied with water to provide water column between head and component

摘要

The wall thickness measurement is performed using a pair of diametrically opposing measuring heads (16) in the path of the plastics component (4) between an extruder (1) and a cooling trough (6) subjected to an oscillating rotation through 180 degrees. Each measuring head (16) has an ultrasonic source (25) within an open measuring chamber (27), to which water is fed via a flexible line (22), to provide a water column between the ultrasonic source (25) and the plastics component. Pref. the measuring heads (16) can be operated in a multiplex measuring mode. An electronic transmitter (35) and receiver (36) are connected to the ultrasonic source (25). A microprocessor (32) generates multiplex excitation pulses (C) and analyses echo signals. USE - For measuring wall thickness of extruded plastics cable insulation.