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The following diagrams show typical
survey train configurations. When
assembling any survey train, please
be careful of the following;
do not use
pipe wrenches on the instrument
and
always check to make sure the
battery compartment and data port
plug are firmly closed to prevent
water damage. Ensure the
arrow on the instrument points into
the hole (away from the cable
swivel).
Cable Lowered Surveying has many
applications which include; site
engineering, open hole, reverse
circulation, where the hole is
steeper than 45°. Holes between 35°
to 45° from horizontal can also be
surveyed with the addition of roller
assemblies.
Configurations
Configuration 1
Holes that are close to the diameter
of the instrument do not require
centralization and therefore the
survey train only requires the
following items;
|
1 – cable swivel |
4 – instrument |
|
2 – female-female
coupling |
5 – female-female
coupling |
|
3 – sinker rod(s)
(optional) |
6 – impact foot. |
A sinker rod (item 3) is only
used if extra weight is required
to reduce the time it takes for
the survey train to get to the
bottom of the hole. In some
applications multiple sinker
rods may be required.
Configuration 2
To increase accuracy in larger
diameter holes, the female-female
couplings are replaced by
centralizers. The survey train would
therefore have the following items;
|
1 –
cable swivel |
4
– instrument |
|
2 – centralizer |
5 – centralizer |
|
3 – extension/sinker
rod(s) (optional) |
6 – impact foot |
A sinker rod (item 3) is only
used if extra weight is required
to reduce the time it takes for
the survey train get to the
bottom of the hole, multiple
sinker rods may be required for
some applications. Extension
rods (item 3) are light weight
versions of sinker rods which
can be used in some applications
to increase the accuracy of
inclination readings.
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