Elcometer CG20 Operating Instructions Manual page 8

3.2 FITTING THE TRANSDUCER
The transducer transmits and receives ultrasonic sound
waves that the gauge uses to calculate the thickness of the
material being measured.
The transducer connects to the gauge via the attached cable,
and two coaxial connectors. When using transducers
manufactured by Elcometer NDT, the orientation of the dual
coaxial connectors is not critical; either plug may be fitted to
either socket.
The transducer must be used correctly in order for the gauge to produce accurate, reliable measurements.
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