Ultrasonic Thickness Gauge Theory of Operation C-3
April 2004
As with any difficult application, experimentation with actual
product samples is the best way to determine the limits of a
particular gauge/transducer combination on a given surface.
B. Transducer Positioning/Alignment - For proper sound
coupling the transducer must be pressed firmly against the test
surface. On small diameter cylindrical surfaces such as pipes,
hold the transducer so that the sound barrier material visible on
the probe face is aligned perpendicular to the center axis of the
pipe. See Figure C-1 below.
Figure C-1: Proper Alignment of Transducers for
Cylindrical Surfaces
While firm hand pressure on the transducer is necessary for good
readings, the probe should never be scraped along or twisted
against a rough metal surface. This will scratch the face of the
transducer and eventually degrade performance. The safest
technique for moving a transducer along a rough surface is to
pick it up and reposition it for each measurement, not to slide it
along.
Transducer