Installing the 3TB in a borehole
10. Remove the handle, and screw it onto the metal spool of the ratchet
mechanism.
11. Hang the strain relief unit and instrument(s) from the loop at the other end of
the cable. You are now ready to lower the assembly into the borehole as
described above.
4.4 Earthing a borehole sensor
To achieve the best performance from any borehole instrument, you must make sure
that the sensor electronics, its casing and the power supply share a common, local
ground, and that all power and data lines are adequately protected against lightning
and other transients.
This section describes techniques for grounding sensor equipment which have
proved effective in many installations. However, local conditions are always
paramount, and you should design your installation with these in mind. Any
regulations in force at your chosen location must also be followed.
34
Issue G - November 2019
