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ADPRO Passive-Infrared (PIR) PRO Series by Xtralis
Planning and Commissioning Manual
One possible way to avoid false alarms is to use a so-called A/B alarm or ‘double knock’,
that is, two detectors connected.
Only when two detectors go into alarm is there a major alarm.
If this option is chosen, very precise analysis and planning is required.
Even this measure can lead to false alarms if not installed perfectly; when, for instance, there
is very thick fog between the two detectors.