Analysis of the reasons why the ultrasonic thickness gauge value does not display
In practical applications of ultrasonic thickness gauges, especially in the monitoring of in-service equipment, if the indication value is distorted and deviates from the actual thickness, resulting in pipeline (equipment) hidden dangers, the pipe fittings are replaced based on wrong data, causing a large number of Material waste. Mattel will explain to you the reasons why there is no value display or the value is flickering erratically:
(1) The surface roughness of the workpiece is too large, resulting in poor coupling between the probe and the contact surface, low reflected echo, and even the inability to receive echo signals. Most of the equipment and pipelines in service are surface-corroded, and the coupling effect is extremely poor.
(2) The radius of curvature of the workpiece is too small, especially when measuring the thickness of small-diameter pipes. Since the surface of the commonly used probe is flat and the contact with the curved surface is point contact or line contact, the sound intensity transmittance is low (poor coupling).
(3) The detection surface and the bottom surface are not parallel, the sound waves are scattered when encountering the bottom surface, and the probe cannot receive the bottom wave signal.
(4) Due to the uneven structure or coarse grains of castings and austenitic steel, severe scattering attenuation occurs when ultrasonic waves pass through them. The scattered ultrasonic waves propagate along complex paths, which may annihilate the echoes and cause no display. .
(5) There is some wear on the probe contact surface. The surface of commonly used thickness measurement probes is made of acrylic resin. Long-term use will increase the surface roughness, resulting in a decrease in sensitivity, resulting in no display or flickering.
(6) There are a large number of corrosion pits on the back of the object being tested. Because there are rust spots and corrosion pits on the other side of the measured object, the sound waves are attenuated, causing the readings to change irregularly, and in extreme cases there may even be no readings. Ultrasonic Thickness Gauge
