Thermo Scientific LevelPRO Series, Installation Manual

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Hardware Installation
Detector-Transmitter
Thermo Fisher Scientific LevelPRO Installation Guide
3-7
For a strip source, the bottom of the range is at the bottom of the detector’s
sensitive length or at the bottom of the active length of the source,
whichever is higher.
In
Figure 3–5 , the top of the source beam (center of the source housing) is
aligned with the top of the sensitive length of the detector. Thus, the top of
the measurable range is defined by the horizontal line drawn from the top
of the sensitive length of the detector to the center of the source housing.
The bottom of the range (BR), measured from the top of the measurable
range, is provided by the formula:
BR = BD – [PD X BD / SD]
or, equivalently,
BR = BD X [1 – (PD / SD)]
where
BD = distance from top of range to the bottom of the sensitive length
of the detector (in Figure 3–5 , BD = sensitive length of detector).
PD = distance from the center of the detector to the inner vessel wall.
SD = distance from the center of the detector to the center of the
source.