Wet Labs ECO VSF, Руководство пользователя

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18 ECO VSF User’s Guide (VSF) Revision AN 14 Sept. 2011
Figure 5. General geometry of the sensor
The detector (D) and the source (S) are separated by a distance SD.
The angle of the center of the detector beam with the line SD is


.
The half-angle of the detector cone is 

.
The corresponding angles for the source are 

and 

.
The volume above the SD line is broken up into the small volumes  x  y  z. z is in the same
plane as the SD line.
The small volume,
 V =  x  y  z at (x,y,z) was determined by simple geometry. It was then
determined whether the  V was in the intersection of the source beam and the field of view of
the detector (both conical shapes). The intersection of each cone and the plane is an ellipse
and the illuminated area is the intersection of those ellipses. The signal strength was
determined for each elementary volume, and then integrated over the illuminated area to
obtain the weighting function. Weighting functions were determined in this manner for each
source–detector pair (nominal angles of 100, 125, and 150 degrees) and are plotted in the
figure below.
(D
)
detector
(S)
source

d

s

d

s

z

x

y