Operator's guide
5. Join the loop to the boiom of the strain relief mechanism using
the linking cable provided.
6. Using a small winch, hoist up the sensor package and strain relief
mechanism until both are hanging by the lifing cable, with the
strain relief mechanism extended. Tighten the cable clamps on the
strain relief unit, allowing a liile slack in the signal cable.
7. Fix the signal cable to the main lifing cable about 1 m above the
strain relief mechanism using a metal clamp (a nylon cable tie
may be sufcient for shallow installations.) Leave a liile slack
in the signal cable between the clamp and the strain relief
mechanism.
8. Position the assembly over the top of the borehole. Do not allow it
to drag across the ground.
9. Lower the sonde so that its base is just level with the borehole
mouth. If there is a depth gauge on the winch, set this to zero.
10.Continue to lower the sonde to a depth of about 1 m, so that the
instrument is still visible.
11.Extend the hole lock arm (see
Section 2.5, “Operating the hole
lock”
) to check that it fts your b orehole. T he c urrent d rawn
should dip slightly as the arm touches the casing, then drop to
zero when it is fully extended. Check that the sonde is frmly
anchored to the borehole casing by aiempting t o slacken t he
load bearing cable. If it remains taut, the sonde is still loose within
the borehole. Do not proceed with installation in this case.
December 2004
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