Dakota MAX II, Operation Manual

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98
CHAPTER TEN
BOLT MATERIAL CALIBRATION
10.1 Why Calibrate?
The preset bolt types in the MAX II contain average factors for the material type.
These are approximate values only. In a tightly controlled application where extreme
accuracy is required, it is necessary to obtain all the information possible about the
fasteners being measured. By calibrating the fasteners, the ultrasonic and physical
lengths of the bolts will match. However, if a field calibration is done, a complete
calibration is not necessary. An important thing to note is the fact that everything
done in the calibration process result in average values. Since a sample of fasteners
will be used in the calibration process, and given the slight differences in material, the
result will always be an average value of that sample.
10.2 Velocity Calibration
A velocity calibration is generally performed by adjusting the velocity in the MAX II to
the point where the ultrasonic and physical lengths match. Again, since a sample of
fasteners will be used in this process, the velocities will vary by a very small amount,
thus resulting in an average velocity value. To accurately calibrate the velocity, a
calibrated set of mechanical calipers is required to determine the exact physical
lengths of the fasteners. The following procedure outlines this process.
Calibrating the Velocity
1) Press the MENU key once to activate the menu items tab. Press the MENU
key multiple times to tab right, and the ESC key multiple times to tab left,
until the GEOM menu is highlighted and displaying the submenu items.
Alternatively, press the LEFT and RIGHT arrow keys multiple times
using the left button wheel.