Calibration Methods - Elcometer NDT MTG6 Gebrauchsanleitung

7 CALIBRATION METHODS

In order for the gauge to make accurate measurements, it must be set
to the correct sound-velocity for the material being measured.
Different types of material have different sound-velocities. For
example, the velocity of sound through steel is 5920m/s
(approximately 0.233in/µs) and the velocity of sound through
aluminium is 6350m/s (approximately 0.248in/µs).
Setting the calibration is crucial for the gauge to function correctly. The
calibration procedure should be performed when the measurement
mode, transducer and / or material type is changed.
A choice of calibration methods is available, depending on the
measurement mode selected, see Table 3: Calibration Methods.
To select the calibration method, press Menu/Calibration/Cal Method.
Calibration
Method
1 Point
2 Point
en-13
R
TABLE 3: CALIBRATION METHODS
Icon Description
This is the simplest and most commonly used
calibration procedure. After setting the zero point
- see Section 6 'Setting the Zero Point' on page
en-12 - a reading is taken and adjusted on an
uncoated sample piece of test material of a
known thickness. Once the thickness has been
entered and confirmed, the derived sound-
velocity is displayed.
This method allows for greater accuracy over
small ranges. Readings are taken and adjusted
on two uncoated sample pieces of test material,
of two different and known thicknesses. Once
the second thickness has been entered and
confirmed, the derived sound-velocity is
displayed.
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