Checkline TI-25P - Manual (Page 6)

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M Symbol: When the M symbol is on,
in conjunction with the /s symbol, the
TI-25P is displaying a sound-velocity
value in meters-per-second.
3.3 The Transducer
The transducer is the “business end”of the TI-25P. It transmits and receives
the ultrasonic sound waves which the TI-25P uses to calculate the thickness
of the material being measured. The transducer connects to the TI-25P via
the attached cable and two coaxial connectors. When using the transducer,
the orientation of the dual coaxial connectors is not critical: either plug may
be fitted to either socket in the TI-25P.
The transducer must be used correctly in order for the TI-25P to produce
accurate, reliable measurements. Below is a short description of the trans-
ducer, followed by instructions for its use.
This is a bottom view of a typical transducer.
The two semicircles of the wearface are
visible, as is the barrier separating them.
One of the semicircles is responsible for
conducting ultrasonic sound into the material
being measured, and the other semicircle is
responsible for conducting the echoed sound
back into the transducer. When the transducer
is placed against the material being measured,
it is the area directly beneath the center of the
wearface that is being measured.
This is a top view of a typical transducer.
Press against the top with the thumb or index
finger to hold the transducer in place.
Moderate pressure is sufficient, as it is only
necessary to keep the transducer stationary,
and the wearface seated flat against the
surface of the material being measured.
1.8.8.8.8
+ INM M /µ s
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An additional important consideration when measuring laminates is that
any included air gaps or pockets will cause an early reflection of the ultra-
sound beam. This effect will be noticed as a sudden decrease in thickness in
an otherwise regular surface. While this may impede accurate measurement
of total material thickness, it does provide the user with positive indication
of air gaps in the laminate.