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Figure below: Measuring the second point during two-point calibration.
7. Repeat steps 2 to 6 at the second calibration point.
8. Finally, press the
/ F3 key to complete the two-point calibration. The meter
is now ready to take measurements within this range.
5.5 perform measurements
When the instrument displays thickness measurements, the display shows the last
measured value stored until a new measurement is performed.
In order for the transducer to fulfil its task, there must be no air gaps between the wear
surface and the surface of the material to be measured. This is achieved by using a
"coupling liquid", which is usually called "coupling agent". This liquid is used to transmit
(couple) the ultrasonic waves from the transducer into the material and back again.
Before attempting to perform a measurement, a small amount of coupling agent should
be applied to the surface of the material to be measured. Normally a single drop of
coupling agent is sufficient.
After applying the coupling agent, press the transducer (contact surface down) firmly
against the area to be measured. The Coupling Status Indicator should be displayed
and the display should show a numerical indication. When the unit is properly set to
"zero" and the correct sound velocity, the digit on the display will show the actual
material thickness directly below the transducer.
If the coupling status indicator does not appear or does not appear stable, or if the
digits on the display appear irregular, first check that there is a sufficient coupling agent
film under the transducer and that the transducer is flat on the material. If this condition
persists, it may be necessary to select a different transducer (size or frequency) for the
material to be measured.
While the transducer is in contact with the material to be measured, the instrument
performs four measurements per second by continuously updating its display. When
the transducer is removed from the surface, the display shows the last measurement
taken, stored in memory.
