Abus Smartvest FURM35000A Bedienungs-, Installations- Und Wartungsanleitung Seite 45

If the detector's battery charge falls below a certain value, the detector
signals this with an acoustic warning tone (every 40 seconds). If this warning
signal sounds, the detector batteries must be immediately replaced with new
batteries. Pressing the Test button mutes the fault signal for 8 hours.
From the time of the first battery warning signal, the detector is
still operable and completely functional for at least 30 more days.
Self-test with automatic error message
The smoke alarm device periodically runs a self-test.
If the trigger sensitivity of the detector falls below the required minimum
threshold (e.g. as a result of excess contamination of the smoke
measurement chamber), the detector beeps once every 40 seconds.
Pressing the Test button mutes the fault signal for 8 hours.
If the error message does not clear after the detector has been
cleaned, the detector must be replaced immediately (see "Care
and maintenance" chapter).
Displays and functions
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