THORLABS M2MS, Руководство по эксплуатации

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BP209 Series 6 The Graphics User Interface (GUI)
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21424-D02
When "User Rectangle" is selected, please enter
size and position of the Calculation Area numeri-
cally or drag and drop the borders of the user rect-
angle. All values are in µm, and the point of origin is
situated in the upper left corner of the entire sensor
area. X (Y) Positions describe the position of the left
(upper) border of the user rectangle (ellipse).
The Calculation Area can also be set and visualized
within the
2D Reconstruction window. See the
appropriate chapter for details.
Clip Level of the Calculation Area
If the calculation area is detected automatically
(
Auto Rectangle ), the borders of the Calculation
Area in all four directions are defined by the calcula-
tion area clip level. The border in one direction is set when all pixel values fall (seen from the
peak) below the Clip Level. Decreasing the Clip Level increases the Calculation Area which in
return increases for example the 4
s diameters, but also increases the noise. For a steep beam
profile, 1.0% is an optimal clip level value. If the beam profile is rather flat, it might be advant-
ageous to lower the clip level.
The clip level is set by default to 1 % and can be set between 0.01 and 13.5 %. In order to
quickly return to the recommended 1.0% clip level, just click to the box
Default (1.0%) .
Note The " Clip Level of Calculation Area" is different from the Clip Level used for beam
profile calculations!
Attention
The calculation area must not cut off lower intensity parts of the beam profile. This may
cause inaccurate calculation results!
6.5.4.2 Averaging Mode
Three modes are available - floating, block and rolling.
When using an averaging mode, please also define the number of averaged frames, which can
be set from 1 to 100.
In Floating mode , the average is calculated from the weighted previous average and the re-
cent frame. Example: Floating average is made for 10 frames. The previous average value is
multiplied by 9, then the recent frame value is added and the sum is divided by 10, which gives
the new average value.
In Block mode , the indicated number of frames is accumulated, after acquisition the average is
calculated and displayed. This is the slowest mode.
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