BOREAL LASER GasFinder2, Operation Manual

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3.8
Boreal Laser Inc. GasFinder2 Operation Manual — Installation July 17th 2017
Divergence
The laser beam, when it is emitted from the GasFinder2, is about 1.5mm in diameter. It
diverges at about 1.5 milli-radians, so at 100m the diameter of the beam is 150mm and
at 600m the diameter is about 1m. This divergence allows for a small movement of the
Gasfi nder2 without becoming mis-aligned, however there is a ‘ sweet spot’ in the centre of
the beam which should always be used when making the initial alignment. This is where the
returning light value and the signal strength are at a maximum.
Magnetic Fields
It has been found that exposure to high magnetic fi elds, as would be experienced in an
aluminium smelter, can cause problems with the
GasFinder2 . In such cases the Instrument
‘locks up’ and the menu cannot be accessed. In most cases the instrument will return to normal
operation when removed from the infl uence of the high magnetic fi eld. It is recommended
that the instrument not be used closer than 1m to a busbar carrying 100,000 amperes or 2m
from one carrying 200,000 amperes.
Divergence angle ‘a’
is 1.5mR
or 3.44 minutes of arc
a
‘Sweet Spot’
Retros
High
current
busbars
Minimum
1m