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The transducer must be used correctly in order for the TI-25DLX to produce accurate,
reliable measurements. Below is a short description of the transducer, followed by
instructions for its use.
This is a bottom view of a typical transducer. The two semicircles of the wear face
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 wear face that is being measured.
This is a top view of a typical transducer. Press against the top with the thumb or index
nger to hold the transducer in place. Moderate pressure is sufcient, as it is only
necessary to keep the transducer stationary, and the wear face seated at against the
surface of the material being measured.
Measuring
In order for the transducer to do its job, there must be no air gaps between the wear-
face and the surface of the material being measured. This is accomplished with the use
of a “coupling” uid, commonly called “couplant”. This uid serves to “couple”, or
transfer, the ultrasonic sound waves from the transducer, into the material, and back
again. Before attempting to make a measurement, a small amount of couplant should
be applied to the surface of the material being measured. Typically, a single droplet of
couplant is sufcient.
After applying couplant, press the transducer (wear face down) rmly against the area
to be measured. The Stability Indicator should have six or seven bars darkened, and a
number should appear in the display. If the TI-25DLX has been properly “zeroed” (see
page 15) and set to the correct sound velocity (see page 16), the number in the display
will indicate the actual thickness of the material directly beneath the transducer.
If the Stability Indicator has fewer than ve bars darkened, or the numbers on the
display seem erratic, rst check to make sure that there is an adequate lm of couplant
beneath the transducer, and that the transducer is seated at against the material. If the
condition persists, it may be necessary to select a different transducer (size or frequency)
for the material being measured. See page 7 for information on transducer selection.
