Super-sensitive smoke alarm

[bungeejumper]

We recently fitted a couple of those super-duper optical smoke alarms that shriek, shine a light and generally dance the can-can whenever smoke is detected. (By sight, not by smell.) So far, so good. We're all against smoke, after all. And the Fire Angel is there to protect us.

Ours, however, goes off far too often. A little bit of light sanding in a doorway fifteen feet away? Aaargh, goes the optical sensor, I see smoke, and all hell breaks loose. A lorry passes by while the front door is open. Evacuate, evacuate!

Is it faulty? Or are they all designed to be this trigger-happy?

BJ

[Dorn1]

Certainly sounds like a fault.
They're designed with a light source and sensor separated by a non-reflective (matt black) path so that the smoke particles bounce the light around to trigger. Either yours has got some dirt in it (maybe dust during drilling from installation) or maybe the "lid" has come off the sensor inside*. or the electronics is "rubbish" and it should never have left the factory!
Either way, take it back to the supplier.
*-we had one start going off after a few years, I eased the lid off and found much dust and a small spider, all hovered out and cleaned with meths and cotton bud.
HTH
C

[csearle]

...we had one start going off after a few years, I eased the lid off and found much dust and a small spider, all hovered out and cleaned with meths and cotton bud.

Yes these things need to be kept clean. I used to work on software associated with optical smoke detectors and recall that the ones fitted in factories had a cleaning schedule, where they were periodically returned (to "our" factory) for cleaning.

The software integrates the returns from the photodetector over a period of samples and triggers the alarm if this integrated value crosses a threshold. In "ours" the base reflection level was also monitored to detect early contamination in the chamber and raise a maintenance report.

Regards,
Chris