APPENDIX
Measuring Table
In this measuring table standard emitters are prepared for 6 di
ff
erent nuclides which can be
released in any failures in nuclear power stations; these are standard emitters with 100 Bq and
1,000 Bq. The impulses per minute during the measuring time of 10 minutes were recorded
with the calculated background count of the radiation detection tubes deducted. These are
therefore the net impulse frequencies (without background radiation).
A distance of 30 mm was chosen for this measurement. Smaller distances give higher impulse
frequencies and larger distances correspondingly lower counting e
ffi
ciencies.
Impulses per minute Ipm
NUCLIDE
END WINDOW COUNTER TUBES -
IMMERSION COUNTER TUBES
100 Bq
Type A
Type G
Type B
Type FSZ
J-131
26.2
63
13.5
27.5
Cs-137
35.6
143
27.3
52.3
Sr-90
36.0
155
29.1
59.0
Sr-90 + Y-90
84.6
363
100.3
203.4
Uranium
15.9
64
28.9
57.0
Thorium
19.3
74
31.2
62.1
1000 Bq
Type A
Type G
Type B
Type FSZ
J-131
262
626
135
275
Cs-137
356
1431
273
523
Sr-90
360
1550
291
590
Sr-90 + Y-90
846
3630
1003
2034
Uranium
159
638
289
570
Thorium
193
744
312
621
OPERATING INSTRUCTIONS
for Counter Tube Type G
JS Monday 10 January 2011 Page 8 of 9
