
M5-CYG4P-M-01_Iss5.doc
Cygnus 4+ Operating Manual
35
The A-Scan display can assist you - you will see an unclear
ultrasound signal with unclear back wall reflections.
This A-Scan shows an incorrect
measurement that may be from
measuring couplant inside a pit.
Echo-Echo Mode
Like Single Echo mode the A-Scan can be very useful when taking
measurement through coating using Echo-Echo mode. Echo-Echo
mode measures thickness by measuring the time between two
consecutive echo signals, in ideal conditions this is a good reliable
method of thickness measurement thorough coating, but when
corrosion starts to degrade the echoes the gauge could measure
between two incorrect echoes and give a wrong reading. Here the
Corroded Metal
Couplant
Probe
Avoid Measuring Directly Over Corrosion Pits.
Pit