LB 124 Scint 5. Contamination Measurements
37
If you are dealing with a compound of radio nuclides and you
know the individual nuclides, you make use of a so-called trac-
er; this will either be the nuclide that is the major constituent of
the compound, or the most dangerous one (with fresh fission
products, this will almost always be iodine-131).
Attention! This does not mean that in this measurement mode,
the monitor is able to measure purposefully and selectively the
contamination caused by a specific radio nuclide within a com-
pound. It just values the contamination as if it was caused by
the respective radio nuclide.
B-1 or B-2 In this measurement mode, a conversion factor is used that the
user has entered and that refers to a singular nuclide or nuclide
compound that is not part of the nuclide library of the LB 124
Scint.
This measurement mode is used when
a) you wish to measure a nuclide that is not part of the nuclide
library. For this purpose, the device has to be calibrated with
the help of a respective test source
b) you wish to measure a specific nuclide compound consisting
of some of the nuclides from the nuclide library.
5.3 Accuracy of the Display in Bq/cm²
The calibration factors determined by the manufacturer and
stored in the LB 124 Scint in the setting A-100 (see chapter
6.8.3) for the indication in Bq/cm² refer to calibration sources of
10 cm x 10 cm and to a surface emission rate certified by the
German Calibration Service DKD.
Comparative measurements with other devices also indicating
their results in Bq/cm² will therefore only produce corresponding
results, if these devices have also been calibrated with sources
of the same kind. If, in your comparative measurements, you
get results differing from the ones that the LB 124 Scint dis-
plays, please check whether
a) the same radio nuclide has been selected and
b) the source used for the calibration meets the requirements
mentioned above.
For surface contamination measurements, the extent of the
contamination in relation to the standardized area of 100 cm² of
the calibration source has to be taken into account as well.
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