Berthold DUO XPERT LB 470RID, Operating Manual

Page: 135 / 240

LB 470RID Level 7 Main Menu Device Setup
56925-1BA2 Rev.02, 05/2021
135
Detecting Interference Radiation XIP
1
2
3
4
5 Pipe
Welding seam tests with X-rays
Radiation interference
Distance up to 200 m
Level Measurement
Fig. 108 Interference radiation during a weld inspection
Detecting Interference Radiation
The high Gamma sensitivity of scintillation detectors may cause a false reading. To
detect interfering radiation, a double plausibility check can be enabled.
The alarm is triggered by:
Scenario A - Maximum possible count rate (empty calibration)
Is > Io * 1.5
Is = current count rate in cps integrated over one second
Io = maximum count rate at empty calibration
Scenario B - Mean value of current count rate monitored
The system sensitivity, i.e. the distance of the alarm thresholds is defined as the
multiple of the mean statistical variations and can be entered as Sigma value as
needed. The time constant is one second.
When reaching the alarm threshold, a message is output via the error relay and on
the device display.
Is > Im + n * Sigma
Im = current count rate integrated over one second
n = multiple value of Sigma