Chapter 5 Explanations
Mini-Switch LB 471
5.4 Interference Radiation Detection
The high Gamma sensitivity of scintillation detectors may have the
effect that interference radiation aimed at the detector (e.g. radia-
tion emitted during welding seam tests) may trigger a false alarm
or not trigger an alarm.
A simple automatic plausibility check can be enabled to detect in-
terference radiation.
The alarm is triggered by the following condition:
Is > Io * 1.5
Is: live count rate (code 13)
Io: empty count rate (code 20)
Function affected by interference radiation.
This type of interference radiation detection does not trigger any
alarm if the count rate increase due to interference radiation is
below 1.5 x ECR.
For welding seam tests in the vicinity (approx. 300 m) of the
measurement point the control center or the production have to be
informed and, if necessary, the control has to be set to “manual”.
Figure 13:
Measurement affected by
welding seam test
Welding seam test
on pipeline
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