Dakota MAX II, Operation Manual

Page: 53 / 216

MAX II Bolt Tension Monitor
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Figure 3 Effect of lowered and raised grade marks
6.3 Bolt End Reflectors
Smooth, flat reflecting bolt ends that are perpendicular to the axis of the bolt are
required for accurate echo reception. Bolt ends may need to be cleaned, ground, etc.
to achieve the required surface.
Note: Misalignment exceeding 2 degrees can cause significant errors.
Avoid:

Rough reflecting bolt ends. As shown in Figure 4, if the reflecting end of the bolt is
rough or curved, most of the reflected energy will be dispersed and a weak or
distorted echo will be received.

Reflecting bolt ends not perpendicular to the axis of the bolt. Sonic energy will be
reflected toward the sidewall of the bolt, as shown in Figure 5.

Nonperpendicular reflecting bolt ends due to bending of the bolt as shown in
Figure 6.
Figure 4 Rough reflective surface
Figure 5 Non Parallel reflecting Surface