ORTEC Detective X, Руководство пользователя

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ORTEC
®
Detective
®
X Handheld Radioisotope Identifier 1107231N / 082020
78
5.3.3 Distance Optimization
New to Sleuth is the source distance optimizer indicator. This indicator suggests
that operators move closer to a source or farther away from it in order to
optimize data collected for analysis at the Reachback facility.
If deadtime is less than 25% or gamma count rate is less than 15,000 cps, the
operator is directed to move closer (see Figure 101). This indicator flashes
yellow.
If deadtime is greater than 40% or gamma count rate is greater than 20,000 cps
the operator is directed to move back (see Figure 103). This indicator flashes
red.
Otherwise the indicator shows “Distance from Source OK” (see Figure 102) in
green.
Note that once an operator initiates an IPC measurement actual distance will
be requested and this indicator will show that entered value (see Figure 104).
Also note that this a is passive indicator only and it in no case actively prevents
collection of data.
NOTE Regarding “System Background” versus “5 min BKG” Nomenclature:
The “5 Min BKG” referred to by the Sleuth application is sometimes called a “Blank”
measurement by various organizations. The term “System Background” is used elsewhere
in the Detective X system to denote a 30-minute (ideally) measurement made to help setup
Stabilizer values, establish expected count rates, reduce false-positives on NORM IDs, and
ensure a properly running system.
A valid and representative “System Background” is important in the analysis of the
spectrum in the Detect and Identify modes of the traditional Detective X interface.
Detective X maintains separate background data for the system based upon each accessory
potentially mounted to the front of the unit (neutron detector, collimators, passive detector
cover).
While the Sleuth application does not require the user to perform a traditional System
Background prior to other Sleuth measurements, it should be noted that the user may
experience nuisances such as false-positive NORM IDs or stabilizer issues.
These issues can be corrected by utilizing the Detective X interface to perform a “System
Background”.
Figure 103. Move Back
Figure 102. Distance OK
Figure 101. Move Closer
Figure 104. Distance
Entered