BOREAL LASER GasFinder2, Руководство по эксплуатации

Страница: 44 / 74

7.6
Boreal Laser Inc. GasFinder2 Operation Manual — Troubleshooting July 17th 2017
Types of Supports
All posts require a solid concrete base. In areas where freeze/thaw
conditions occur, the base of the concrete needs to be well below the
frost level and an air space left between the base and the surrounding
earth down to the frost level. Above ground, the post can be concrete
(preferred) or metal. A 100mm x 100mm (4”x 4”) metal post can be used
for heights up to 2m; above 3m, torsion limits the path length to 100m.
Longer distances or higher supports require a wider base. This can be obtained
by using self-supporting lattice towers or a number of posts joined at the top
and well braced.
Provided it is in the correct location, a building can often provide a very stable
support for a remote head. However it should be noted that the metal roof
structures of long buildings oriented east-west are very susceptible to diurnal
movement caused by solar heating.
Scaffolds can be used for temporary mounting
structures but they must be ‘CupLock’, ‘Z-Lock’
or other rigidly braced types. The clip-together
types are not stable enough. To comply with
safety regulations, the height of a scaffold
cannot exceed three times the width of the
narrowest base dimension. This gives a very
stable platform. The scaffold can also be placed
on adjustable legs to accommodate different
ground elevations.
Thermal Effects
Differential heating of support legs can cause diurnal variations in alignment. This is very
common on long paths (over 100m) and can be minimized by shading, insulating the legs,
or using non-metallic materials such as concrete, wood, or fi breglass. The effect can be seen
by looking at the
light level history over a number of sunny days. A sinusoidal variation is an
indication of solar heating. In severe circumstances a dispersed retro array may be the only
solution.
Wind Effects
On outside paths these effects can be minimised by using open-
member supports. Note that guy wires can sometimes oscillate
and cause movement.
Platform Separation
Note: It is critical that the platform for the GasFinder2 is not
connected to the same platform that the operator stands on
for installation or maintenance work. This may preclude the
use of scaffolds for long paths.
GasFinder mounted separately from
the work platform
Measuring Landfi ll Gas
Solid metal support
Photo by M. Ball
Scaffold support