TU_US-BA-e-1714
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In addition, measurements performed through very thick paint or coatings may result
in the paint or coating being measured rather than the material intended.
The responsibility for a proper use of the instrument, as well as the recognition of these
types of phenomenon solely depends on the user of this instrument.
5.6 Two-point Calibration
This procedure requires that the testing person has got two known thickness points on
the test pieces which are representative of the range being measured.
1) On the
【
Test Set
】－
>
【
2-Point Cal
】
submenu item the
key has to be pressed
to switch ON the Two-point mode. Then the menu has to be left to get to the measure-
ment screen of the instrument
. The string “DPC” will appear on the operation hint area
of the main measurement screen.
2) The
key has to be pressed to start the calibration procedure. The string “NO1”
will appear on the operating hint area, indicating measuring the first point.
3) A small amount of couplant has to be applied to the sample piece.
4) The transducer has to be pressed against the sample piece at the first / second
calibration point. It has to be made sure that the transducer is placed flat on the surface
of the sample. Now the display should show any (probably incorrect) thickness value
and the coupling status indicator should appear steadily.
5) As soon as a stable measurement is achieved, the transducer is to be removed. If
the displayed thickness distinguishes from the value shown while the transducer was
coupled, step 4 is to be repeated.
6) The and the
key are to be used to adjust the material thickness up and down
until it matches the material thickness of the sample piece.
7) The
key has to be pressed to confirm. The hint will change to “NO2” indicating to
be ready to measure the second calibration point.
8) Steps 3 to 7 are to be repeated. The hint will change back to “DPC”.
The instrument is now ready to perform measurements within its range.
5.7 Scan mode
While the instrument excels in making single point measurements, it is sometimes nec-
essary to examine a larger region, searching for the thinnest point. This instrument
includes a feature, called SCAN- Mode, which allows to do just that.
During normal operation, it performs and displays four measurements every second
which is adequate for single measurements. In SCAN- Mode, however, the instrument
performs ten measurements every second and displays the readings while scanning.
While the transducer is in contact with the material to be measured, it is always keeping
track t
o finding the lowest measurements. The transducer may be “scrubbed” across
the surface, any brief interruptions of the signal will be ignored. If it loses contact with
the surface for more than two seconds, the instrument will display the smallest meas-
urement it found.
