ECOTEST MKS-05 TERRA Operating Manual page 123

Then switch the dosimeter to the mode of surface beta-particles flux
density measurement, and set 10 % value of the specified statistical error
according to item 2.3.3.9 of the OM.
Place the dosimeter with the open window above the 4CO source
surface, providing surface beta-particles flux density from 50 to
2
150 part./(cm ·min), so that the work surface of the detector is placed
completely over the active surface of the source.
Wait until the statistical error of surface beta-particles flux density
measurement results goes down to the value of not more than 15 %.
Then register five measurement results with 5 s interval, calculate the
average value of surface beta-particles flux density and the main relative
error of measurement.
Place the dosimeter with the open window above the 4CO source
surface, providing surface beta-particles flux density from 1000 to
2
10000 part./(cm
completely over the active surface of the source.
·min), so that the work surface of the detector is placed
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