Elcometer CG60DL Operating Instructions Manual page 44

Material being
Mode
measured
Thin materials PULSE-ECHO
(P-E)
High temperature PULSE-ECHO
and
ECHO-ECHO
Noisy material
Measuring
extreme
curvatures or
areas of restricted
access
42
Transducer type
required
High frequency
transducers are required;
typically the 7.5MHz and
10MHz models with extra
resolution.
Special 2.25MHz and 5
MHz High temperature
transducers are required.
Select a higher frequency
transducer to reduce this
noise - 7.5MHz and higher
for better resolution.
Higher frequency
transducers with smaller
diameters are required.
The smallest diameter
uses 3/16" crystals with a
contact area of .250"
Notes
The higher frequencies provide
greater resolution and a lower
minimum thickness rating overall.
Echo-echo mode will eliminate error
caused by temperature variations in
the delay line of the transducer.
Materials such as titanium, stainless
steel, and aluminium may produce
surface noise. This is a signal that
appears at the surface of the
material when using a dual element
delay line probe.