HBM FS42, Руководство пользователя, Страница: 68 / 76

Graphical User Interface
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A4250-5.0 HBM: public
FS42
The normalized threshold value for each Optical Channel
can be inserted on the Threshold box (number
4 in
Fig. 6.20 ) and can be shown graphically in the OSA
graph (number 5 in Fig. 6.20 ). This is an important
parameter, and must be set so that all FBG spectrum
peaks are above the line and that only one peak per FBG
sensor appears over the line.
For definition please refer
to section 5.3.3, on page 37 .
Graphic Tools
Tools to manage the graphical representation are avail­
able on the buttons above the graph (number
6 in
Fig. 6.20 ).
Fig. 6.21
1 Zoom out - The Spectrum graph can be zoomed in or
out. The Zoom In tool is ready every time the cursor is
on the graph area. Zooming In is only possible on the
horizontal axis. By pressing the Zoom Out button
(number
1 in Fig. 6.21 ) the graph will zoom out to dis­
play the entire optical spectrum range.
2 Linear/log - the vertical scale can be changed from
linear to logarithmic by pressing the Scale button.
With this selection the spectrum is represented in log­
arithmic scale (number
1 in Fig. 6.22) and the normal­
ized threshold value is converted to match Optical
Power units regarding maximum peak acquired value.