6.2
Boreal Laser Inc.
GasFinderAB Operation Manual — Maintenance
June 17th 2017
Airborne Cell (cont)
There are no moving parts and the only optical
maintenance required is to clean the window, mirrors
and refl ecting tape. A visual inspection can be made by
opening the end covers and looking through the cell to
the opposite end. Cleaning requires removal and partial
dismantling of the cell and should only be undertaken
as a last resort.
The window is thin Mylar which is a soft plastic and great
care must be used when cleaning to avoid scratches.
Blow off any dust with canned compressed air and then
use copious amounts of warm, soapy water, rinse with
alcohol and air dry
The mirrors have a fi lm of gold deposited on them and
the surface must not be touched. Blow off any dust with
canned, compressed air
A
.
The IMOS retro may be cleaned with warm, soapy water, or replaced with a new piece.
Note:
The instrument relies on a clear optical path to obtain readings of gas
concentration. Dust settling on the window or the retrorefl ector enclosure must be
cleaned off whenever it degrades the instrument’s performance. The average value for
the light level should be kept at the recommended values as determined at the initial
installation.
The need for cleaning will be indicated by a consistent loss of light, which may result in poor
gas-concentration readings. A check of the
Light History
can determine whether the light
loss is gradual or intermittent. Cleaning intervals may vary from once per week to once per
year depending on conditions and usage.
Fibreoptics
Cleanliness
Cleanliness is of paramount importance when dealing with fi bre optic cables. The core of a
Single Mode optical fi bre is 9 microns in diameter, and a speck of dust can easily block the
signal. It is important to clean the connectors before inserting
them into the couplings. This is done by holding the end of the
connector perpendicular to a clean section of tape and describing
a fi gure of eight movement two or three times. The cleaning tape
is held in a dispenser which exposes a new section of tape as
needed.
Do not use alcohol as it leaves a residue.
Layout
Make sure that fi bres are not being pinched by cable ties and that all bends have an adequate
radius. Both situations are a cause of light loss. A bend radius of at least 2 cm is preferred.
Firbeoptic connections do not deteriorate over time. If they are working well, leave
them alone.
A
These cans are available from camera shops and electronic stores or directly from Boreal Laser Inc.
Cleaning Tape
Mirror
Outside view
of retro end
IMOS
retro
Inside view of
Retro end
Mirror
Inside view of
Tx/Rx end
TX/Rx
Window
Outside view
of Tx/Rx end
Summary of Contents for GasFinderAB
Page 53: ......
