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1. Press MULTI MODE, scroll to COATING ONLY (CT) and press
ENTER.
The measurement screen is displayed.
2. Apply a drop of couplant on the transducer and place the
transducer in steady contact with the probe zero disk (battery
cover) and obtain a steady reading - see illustration.
Note: Disregard the value displayed; it is not important. What is
important is accurately performing these steps to ensure
reliability of the zero calculation.
3. Select MENU/PRB/ZERO COATING and then press ENTER.
A confirmation screen is displayed.
4. Press OK (or ESC to cancel).
When the zero coating process is completed the measurement
screen is displayed.
5. Press MULTI MODE, scroll to COATING ON (PECT) and press
ENTER.
The measurement screen is displayed.
You can now take readings.
8.7 CALIBRATING - FOR A MATERIAL
Sound travels through different materials at different speeds, and in order to measure these
materials accurately the correct sound velocity must be programmed into the gauge. Your gauge
features 3 different ways of doing this
Known material calibration - The material to be measured is selected from a list in the gauge
Known velocity calibration - If the material sound velocity is known this may be entered manually.
Known Thickness Calibration - A sample of the material to be inspected is measured using
alternative means and then used to calibrate the gauge.
•
One Point calibration is the simplest and most commonly used calibration procedure with best
performance over large measurement ranges
•
Two Point calibration uses two samples of different thicknesses, with enhanced accuracy
over small ranges close to the sample thicknesses used
For the highest measurement accuracy use the known thickness calibration as this takes into
account variation in material composition, temperature and a variety of other factors.
KNOWN MATERIAL CALIBRATION
If the material velocity is unknown, and a sample thickness cannot be taken from the material, you
can choose a material type from a list stored in the gauge. For each material stored in the list there
is a corresponding velocity value.
Note: These velocities will not always be an exact representation of the material being tested. Use
these values only if a close approximation is acceptable.
1. Select MENU/CAL/MAT.
2. Press ENTER to display the list of material types.
3. Scroll through the material list until the appropriate material is highlighted.
4. Press ENTER to choose the material type.
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