Every year at exam time someone sets off a fire alarm on our campus to try to get out of taking an exam... and fire alarms are deliberately set off in many other contexts with far worse consequences.

My suggestion is to add a video camera to a fire alarm, with a limited amount of memory for video, which it uses as a cyclic buffer, recording the last 1 or 2 minutes as seen from the fire alarm looking out. When the lever is pulled, the recording stops (or is perhaps saved from RAM to flash memory, if recording directly to flash continuously is not practical)

The recording cannot restart until the alarm is properly cancelled.

This will catch false alarmers on video. It will not be a privacy issue because it is physically incapable of recording more than a minute of two due to the small RAM. And if it is a real fire and the alarm burns down, it doesn't matter, because we don't care who pulled the handle in that case - it's *only* to catch people triggering false alarms.

These would use the tiny surveillance style cameras that are hidden in clocks, radios, fake smoke detectors, airports etc.
-- gtoal, Jul 31 2007

Old School! http://deanhunt.com...ention-of-the-week/
Doh! [gtoal, Jan 18 2008]

Like so many ideas here, it's good in principle but not economical.
-- wagster, Jul 31 2007


Cover camera lens with non-transparent adhesive tape. Wait the requisite number of minutes. Operate alarm with impunity.
-- Texticle, Jul 31 2007


> Like so many ideas here, it's good in principle but not economical.

It's economical if you take into account the cost of the Fire Brigade coming out to every emergency. At least this way they know who to charge for the false alarm :-/
-- gtoal, Jul 31 2007


//not economical// surely, if you only want low-frame-rate video and are happy with monochrome, you could do this for ten or twenty quid?
-- MaxwellBuchanan, Jul 31 2007


On second thought, the adhesive tape is too high tech. Just cover the lens with your hand for 3 minutes.
-- Texticle, Aug 01 2007


Why not have the lens out of the way enough that one can't simply cover it with a hand or tape? Bun for this, although it is a good enough idea that I will not be surprised to find out it is baked.
-- PollyNo9, Aug 01 2007


How about an alarm that gives a little misty spray of UV ink when activated?
-- marklar, Aug 01 2007


This was half-baked in Bruce Sterling's book Distraction, but as far as I know doesn't yet really exist. Therefore, bun. More because the book is fantastic than for any reason pertaining to this idea.
-- moomintroll, Aug 01 2007


+ I say OK. If the camera is unknown to the prankster, it could work like [PollyNo9] says, but someone knows it's there, it would be useless.
-- xandram, Aug 01 2007


should be a requisite on high school campuses. +
-- k_sra, Aug 01 2007


1) it could beep for a minute if the view goes black thus drawing attention to anyone covering the camera. Wouldn't matter much that it beeps when the building shuts down for the night as there's no-one left there when the lights are turned out anyway.

2) yes, I did realise it would be less effective if people knew one of these was in place, but how many people look at the clock in the school corridor and assume it's a security cam? Which it could well be... On the other hand, though less effective at catching them, it might be more effective as a deterrent...

3) Running a wire to the camera and housing it out of reach is definitely an option, but not as simple to install as a straight replacement for the existing alarm handle. And people if determined can always wear balaclavas or hoodies. However doing so looks suspicious in its own right and draws attention to the perpetrator. An alternative for the 'sidle up to it and cover it nonchalantly with your hand' problem might be just to use a wider-angle lens so you have a field of view that doesn't permit sidling. (Although now I think about it, that might need a stickie-ootie fish-eye lens which would be more obvious than the usual pinhole)

4) Haven't read "Distraction" but thanks for the pointer; I do like Sterling. He got me at The Difference Engine (at least, the techie bits thereof). Mind you I was never sure if those bits were him or Gibson.
-- gtoal, Aug 01 2007


Some combined security and fire alarm systems have routines where if a break glass point is activated, the cctv cameras in the area turn to cover the area of the fire alarm.
-- oneoffdave, Aug 01 2007


/use a wider-angle lens so you have a field of view that doesn't permit sidling/

Ineffective. The camera will have overwritten the offender walking up to the camera with the latest 2 minutes of palm-covered lens footage.

That's why you need to cover the lens for 3 minutes before activating the alarm.
-- Texticle, Aug 01 2007


I'm thinking you're going to look suspicious standing for three minutes with your hand over a camera by a fire alarm, textual.
-- k_sra, Aug 02 2007


My school had ink-spraying fire alarms. If there was a false alarm, all you had to do was ask everyone to pull their hands out of their pockets. The kid with purple mitts? Arrest that one, officer.
-- shapu, Aug 02 2007



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