Cygnus DIVE Operating Manual
M3-DIVE-M-ENG_Iss9.docx
Page 42 of 117
10.
Interpreting the A-Scan Display in Multiple
Echo Mode
The A-Scan display shows the actual ultrasound echo pulses as
seen by the gauge, these echo pulses are used by the gauge to
determine the thickness measurement if possible.
In Multiple Echo mode the gauge works by generating a short
pulse of ultrasound that is coupled into the object you are
measuring. This pulse then travels through the object (both paint
and metal) and is reflected back to the probe as an echo by either
the back-wall of the object and/or any internal flaws or corrosion
pits. This echo pulse will then continue to reflect back and forth
inside the object until it finally runs out of energy. Each time the
echo pulse hits the probe surface a signal is received by the DIVE
gauge, this signal is shown on the A-scan display as an echo peak.
UT Probe
Ultrasound
from probe
1
st
back-wall
reflection or ‘echo’
..reflects back
again..
2
nd
back-wall
‘echo’
..reflects back
again..
3
rd
back-wall
‘echo’
