ECOTEST STORA-TU RKS-01 - Page 106

104
Fix the radiometer in the УПГД-3В carriage holder so that the mechanical
center of gamma beam coincides with the center of the gamma and beta 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 radiometer in the position,
where DER from
137
Cs source is 0.8 µSv/h, and wait until the 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.
Calculate the DER value
)10(
*
H

, in µSv/h by the formula:
)10()10()10(
***
Ф
HHH



, (3.1)
where
)10(
*

H

- is an average value of the radiometer readings of source
and external gamma background in µSv/h;