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6. Measure a calibration standard and, if necessary, adjust the zero value until the material
thickness value matches the thickness of the calibration standard - see "Manually Adjusting
the Zero Value" on page 30.
15.5 MANUALLY ADJUSTING THE ZERO VALUE
If you have calibrated the gauge by entering a material type or the velocity value of the material, you
should check and if necessary adjust the zero value.This step requires a calibration block.
1. Select MENU/CAL/ZERO.
2. Use the LEFT and RIGHT keys to scroll the value, or press ENTER to open the digits edit box
and adjust the value using the navigation buttons.
3. Press OK to set the value and return to the menu screen, or ESC to cancel.
4. Press MEAS to return to the measurement screen.
15.6 KNOWN THICKNESS CALIBRATION
If the sound velocity of a material is unknown, a sample with two known thicknesses can be used
to determine the sound velocity. If a sample is not available, calibration standards representing the
minimum and maximum thickness of the overall inspection range intended are required. They must
also be of the same material type as the intended application. The example of thickness calibration
given in this section uses a 1" and a 4" standard for calibration.
Note: This section describes performing a calibration using a straight beam contact transducer.
Single and dual element probes may be calibrated in this way. Further information can be found on
the Elcometer NDT website on www.elcometerndt.com.
LOAD THE DEFAULT SETUP
The gauge will require a few basic adjustments in order to get underway with the calibration
process. For this example the default setup will be loaded as a starting point.
1. Select MENU/SETUP/DEFAULT SETUP.
2. Press ENTER.
3. Press OK.
4. Press MEAS to return to the measurement screen.
SET THE RANGE
Set the range so that peaks from the small and large calibration samples are visible on the display.
Our calibration range for this example is 4". Therefore setting a range of 5" will enable you to view
the entire range on the display.
Use the hot menu to adjust the RANGE value to 5".
30
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