I finally found the apartment where the noise is coming from.
So I spoke to the resident (a tenant) and his answer was very bizzare. He said that a qualified person had come to inspect, and told him that the beeping noise is due to particles in the air and not a flat battery.
The person inspecting said there is no problem, and took no action.
So the particles happen to enter the smoke detector exactly every 30 seconds, 24/7 ? Very strange explanation.
In any event, the tenant obviously is not annoyed by the sound (personally it would drive me insane), and had some “expert” declare that there is no problem.
With the tenant obviously lacking in enthusiam to fix the problem… is there anything I can do now?
