Sequoia LISST-SL, Руководство по эксплуатации

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LISST-SL V2.1
User’s Guide
19
SETUP
2. Background
File
acquisition
3. Instrument
health check
Background good?
Pitot Tube clear?
Next proceed as follows:
On the TCB, from the MAIN MENU, use the
SET UP button to set instrument clock, and
units of operation. Return to the MAIN MENU.
Press the CALIBRATE button. Follow
procedures as explained in the preceding
section on TCB. Check off the 3 boxes, and
then also check the View Rings button. At the
next frame, press View Rings button again. In
the background collection mode, the pump
runs at full power. If the rings view is steady,
cancel out, and re-enter the Background mode.
Press Update to capture a new Background file
following
procedure described in the
introduction to the TCB. It will be named
automatically. The new background is shown in
contrast to factory values.
If your background is very similar to the factory value, the
optics are in good health. If not, check which of the
following applies to your data, and what it means.
Your background is higher than factory
background in the middle rings. This means the
optics can be cleaned. Dirt on the windows of
the test cell can explain this excess light.
The inner rings show large amount of light, but
the Lp and Lref ratio is nearly same as factory
value. This may be due to scintillation; it means
that water and instrument temperatures are not
sufficiently close.
The inner rings show large values AND the
L
p
/L
ref
ratio is smaller than factory. In this case,
misalignment of optics is indicated. If the L
p
/L
ref
ratio is 90% of factory value or lower, you may
need to have the optics adjusted by a trained
technician. Please contact your in-country
Distributor or contact Sequoia.
We hope none of the above errors occur. If so, the
instrument is in good shape!
Now, still with the clean water in circulation, cancel out of
the Calibrate mode and press the MEASURE button to
test your background, as before. The display will show
small values on the concentration if the background file
was good. If not, capture another background (make sure
the view rings function shows steady rings).
Check if Pitot Tube is free of air : Air in the pitot system
can cause faulty operation of the iso-kinetic pump
controller. The simplest test is as follows.