ECOTEST DKG-21 M Operating Manual page 100

5.2.7.3.1 During measurement the dosimeter should
be placed close to the phantom surface, directed to
gamma source. The indicator of the dosimeter should be
directed towards gamma source.
5.2.7.4 Calculation of main relative permissible error
limit of DER measurement is performed as follows.
5.2.7.4.1 Prepare
measurement and program zero value of DER threshold
level.
the dosimeter
99
for DER