Optics11 DELTASENS, Руководство пользователя

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13
User Manual
this, the Auto-power tool must be run by opening the “Sensors select” menu and clicking OK. A
popup window will appear to show the tuning progress and automatically close when the tuning is
completed.
It is possible to check if the Auto-power tool correctly tuned the SLD power and the spectrometer
conversion efficiency by analysing the live raw-data acquired by the spectrometer. These data can be
displayed by opening the “RAW data” submenu of the “Dev. Mode” and clicking “Time domain”. In
case of proper tuning the raw signal should resemble the one shown in Figure 7. In case of multiple
sensors connected to the unit, the raw-signal could slightly differ from the one here presented.
However, the envelope shape and the maximum value of the signal should be comparable with the
ones of Figure 7.
For experienced users, the SLD output power and the spectrometer conversion efficiency can also be
set manually. To ensure proper operation of the system the user should tune these parameters in
order to achieve a good Signal to Noise Ratio (SNR) while avoiding signal saturation. The following
guidelines can help the user in performing such procedure manually:
•
Remember to disable the “Auto - power” tool on the “AFE.CTRL” tab of the “Dev. Mode”
menu before performing the following procedure.
•
To display and keep track of the raw signal during the tuning process, open the “RAW data”
submenu of the “Time domain” menu and click “Time domain” .
•
On the “ Settings ” panel the user can control the light output power. Under the “SLD (light
source)” submenu s et the source current to 600 mA and click save at the bottom right of the
"Settings” panel.
•
Now o pen the “AFE.CTRL” tab of the “Dev. Mode” to set the conversion efficiency of the
spectrometer. Find the minimum value of conversion efficiency for which the raw signal still
saturates. Remember to click “Save” to update the spectrometer settings.
•
Now the SLD source current must be lowered in order to achieve a good signal level and avoid
saturation. The “SLD (light source)” submenu of the “Settings” panel allows to display the
maximum of the raw signal spectrum while tuning the SLD source current. Enabl e the “Display
max” option to display the level at which the signal is saturating on the “Spectrum max”
indicator.
•
Tune down the SLD power in order to reach a “Spectrum max” level of around 80% of the
saturation value. Remember to click “Save” on the bottom right of the “Settings” panel for
changes to take place every time you enter a new SLD source current value.