Sequoia LISST-SL, Руководство по эксплуатации

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LISST-SL V2.1
User’s Guide
15
MEASURE
nearly identical to factory value, within 2-3%. Slightly
higher values may occur; that is acceptable. Lower
values of Lp/Lref than the factory value suggests: (i)
turbid or bubble-filled water; (ii) misalignment, or (iii)
scintillation due to temperature difference between the
instrument and the water. More about this in Appendix D.
Drifts in Lref (laser power output) are compensated in
software.
We will also describe how to test your new background
file using the MEASURE function that follows next.
See Appendix D to understand the issues to make an
informed decision on your new Background file.
This completes the Calibration step. If necessary, press
CANCEL a few times to return to the MAIN MENU to
enter the MEASURE function. We repeat:
See Appendix
D to learn more about Background files and when
they are acceptable.
MEASURE/ACQUIRE DATA: This button is meant to
take you to data collection. After familiarizing you, we will
show you how to test your new background file first, and
then how to capture real data in the next chapter.
Pressing the MEASURE button from the Main Menu
takes you to a panel that is titled Acquiring Data. This
panel shows the current instrument depth, sediment
concentration in water, a mean sediment size, water
temperature, river velocity, number of samples saved,
filename, battery voltage and the pump drive voltage and
current drain.
The display is mostly self-explanatory. However, we draw
your attention to the rich data display.
The depth indication is valuable. If you are in the field, the
depth indication tells you exactly how deep the
instrument is,
regardless of the angle at which the cable
hangs [in older USGS standard instruments, the wire