Cygnus 1 User Manual

Introduction
THE MULTIPLE-ECHO METHOD
The Cygnus 1 ROV Ultrasonic Thickness Gauge works on the pulse-echo principle. The
Probe is made to vibrate for a very short period, creating a pulse of ultrasound which enters
the test piece. The Probe waits for returned echos and acting as a receiver, converts them
into electrical signals which are processed to produce timings in digital form.
The multiple-echo beam travel is depicted above, spread out for time, to illustrate the timing
method. The beam path is in fact straight, at 90 degrees to the surface and the ultrasonic
energy reverberates up and down within the metal (as shown in the small sketch above -
left). Each time the echo is reflected back down, a small portion of the energy comes up
through the coatings, striking the Probe which now acts as a receiver.
The delay between echoes at the Probe-face is exactly equal to the time taken to pass
through the metal twice, therefore coatings such as paint are ignored and the measurement
displayed is of the metal thickness only.
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Cygnus 1 Specifications

General

Brand	Cygnus
Model	1
Category	Measuring Instruments
Language	English