30
11) when using
РМ1621А, РМ1621МА dosimeters: repeat measurements
according to article 9) for the reference point where reference DER value is 800,0 mSv/h.
At that seven segments of analogue scale must be indicated;
12) calculate relative measurement error Q
j
, %, by formula
100
.
.
.
.
oj
oj
b
j
H
H
H
H
Q
,
(5.3)
where
oj
H
.
– reference DER value in the tested point;
j
H
.
– average DER value in the tested point;
b
H
.
– average DER value of gamma background in μSv/h equal to 3,0; 80,0
and 800,0
μSv/h and average DER value of gamma background in mSv/h when reference
DER is 8,0; 80,0
и 800,0 mSv/h;
13) Verification results are considered positive, if DER measurement error results
for all tested points, Q
j
, don’t exceed error Q
add
, calculated by formula 5.4.
add
= (10 + 0,0015/
H
+ 0,01
H
) %,
(5.4)
where
H
DER value, mSv/h;
0,0015
– coefficient, mSv/h;
0,01 coefficient, (mSv/h)
-1
.
5.7.3.2 DE measurement main relative measurement error is calculated as follows:
1) set maximum DER and DE threshold levels on the dosimeter and switch on DE
measurement mode;
2) do actions described in 5.7.3.1.(2);
3) read initial DE value from the dosimeter;
4) move the dosimeter on the dosimetric unit so that geometrical center of the
detector coincides with the reference point, where reference DER value from the reference
gamma source
137
Cs is 3,0
μSv/h, and irradiate the dosimeters during T time equal to
60 min;
5) read end DE value from the dosimeter when irradiation is over;
6) calculate main relative DE measurement error Q
j
, in percents, by formula
100
)
(
.
.
T
H
T
H
H
H
Q
oj
oj
Hj
k j
j
,
(5.5)
where
Н
кj
– end DE value, mSv;
Н
нj
– initial DE value, mSv;
oj
H
.
– reference DER value in the tested point, mSv/h;
Т – irradiation time in hours.
7) repeat measurements (1-6) for the reference point, at DER value equal to
80,0 mSv/h during T time equal to 30 min;
8) Verification results are considered positive, if DE measurement error results for
all tested points, Q
j
, don’t exceed
add
= 15%.
Summary of Contents for PM1621
Page 1: ...X RAY AND GAMMA RADIATION PERSONAL DOSIMETERS 1621 Models 1621 1621 1621 1621 OPERATING MANUAL...
Page 13: ...13 Figure 1 2 General overview of the dosimeter...
Page 14: ...14 Figure 1 3 Demounting the clip from 1621 and 1621...
Page 21: ...21 Figure 2 2 Select the 1621 1621 dosimeter operating indication mode...
Page 22: ...22 Figure 2 3 Setting the DE threshold values...
Page 23: ...23 Figure 2 4 Setting the DER threshold values...
