Instruction Manual for MiniTRACE CSDF
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Page 18 08/2012
food mode
(Food)
activate
food
mode
wait 3 sec.
end of food m easurement
activate
control
result of the
measurement
after approx. 2 h.
starts autom.
dose rate < 300 nSv/h
press mode button
press
mode button
saved control measurem ent
in the memory is OK
no control measurement in the memory
or last measurement is > 300 nSv/h
dose ra te > 300 nSv/h
end off food measurement
ac tivate
food
result of the
measurement
after approx. 1.5 h
Figure 10: Food measurement flow chart
Note: You can change the duration of the background (control) measurement using
the MiniTRACE software. But note: the shorter the measurement, the higher the
uncertainty. If you work with a 2-hour measurement time, the result will contain
a 1-sigma uncertainty of 30 % at a background level of 0.1 µSv/h. Be sure to
use an area with a low radiation background, as the lower the background level
the more certain the result. If you do need to measure with a high background
level, try to use a lead castle to shield the measurement system from back-
ground radiation. If your background level is higher than 0.3 µSv/h, food mea-
surement will be blocked and you will get an error message (C ERR) on the
display.
True value At 100 nSv/h At 200 nSv/h At 300 nSv/h
500 Bq/L 500 +/- 30 % 500 +/- 40 % 500 +/- 50 %
Table 3: 1-Sigma statistical uncertainty with different background dose rates
Figure 11: Food measurement
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