ECOTEST MKS-05 TERRA Operating Manual page 117

3.2.4.3 Calculation of main relative error of photon-ionizing
radiation DER measurement
Prepare the УПГД-3В testing equipment for operation according to its
operating manual.
Prepare the dosimeter for photon-ionizing radiation DER measurement
(hereinafter called DER) and program 5 % value of the specified statistical
error according to item 2.3.3.7 of the OM.
Fix the dosimeter in the УПГД-3В carriage holder so that the
mechanical center of gamma beam coincides with the center of the detector,
and wait until the statistical error of external background DER measurement
results goes down to the value of not more than 15 %. Then register five
measurement results of external background DER in the protocol with 5 s
interval.
Place the УПГД-3В carriage together with the dosimeter in the
position, where DER from
statistical error of DER measurement results goes down to the value of not
more than 10 %. Then register five DER measurement results in the
protocol with 5 s interval.
137
Cs source is 0.8 µSv/h, and wait until the
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