One of my schools had an alarming number of particularly mischievous students, who for whatever reason, thought it was funny to pull the fire alarm when there was no actual fire. There would be between 2 to 5 false alarms each year. This must have made the school pretty unpopular with the fire department. I don't know if they ever managed to catch any of the people doing those false alarms because there were no security cameras at that particular school.

I have searched high and low on the internet, and I have found no actual fire alarm switch, nor a retrofit for one, that would spray ink or paint when it was set off. In other words, I don't believe that such things really exist. Several possible reasons I can think of are: #1- The liquid would have to be under some amount of pressure in order to release onto the hand of the person pulling the alarm #2- The liquid would have to be able to remain under pressure and in liquid form for a relatively long period of time #3- If the alarm switch is located in a carpeted area, the ink or paint would stain the carpet if any excess dripped off #4- If the building has fire drills, the manager of the building would end up with ink or paint on their hand which could end up ruining their shirt or coat, so there'd have to be some way to disable the spraying function of the alarm.

I think a solution, at least to the fire department responding to false alarms, would be to have a relatively short period of time between when the alarm sounds, and when it actually calls the fire department. I believe that 1 minute would be enough time if the source of the alarm were close enough to the office, or someone near the source was able to contact the front office and tell them whether it was real or not. If said building had security cameras, the delay could be even shorter, like 30 to 45 seconds, if the security camera monitors were close enough to the controls for the fire alarm system.

During this delay, if the alarm is turned off before the time has expired, it will not send out a signal. The only place one can see whether the signal has been sent or not is at the main control panel. The actual bell, buzz, or beep comes on immediately upon any "alarm trigger" being received (whether it be a fire alarm switch or a smoke detector) so as not to delay evacuation in case there were a real fire. There could also be a "call cancel, bell remain" button so that if the manager/principal/owner/secretary cannot determine the cause quickly enough, he/she can have the building evacuated without calling for help, then go to where the alarm was triggered to find out what happened. This button could also be used to conduct a fire drill, i.e. tell someone else to go pull the fire alarm and then press the call cancel button on the panel

If another alarm source is triggered while the alarm is already sounding, this will override the delay and immediately send a fire department signal, and this includes following the use of the "call cancel bell remain" button. There are several situations where this could be useful:

If a staff member uses the call cancel bell remain button, but then discovers that there is in fact a fire, he/she can pull the alarm a second time which would cause the fire department to be called. Also, if there's a fire far enough from a smoke detector that someone pulls the alarm before the fire alarm detects any smoke, the smoke detector would override the 1-minute delay and cause the signal to be sent right away.

Smoke detectors could be wired up in 2 different groups, one being "normal" (it will trigger an alarm right away) and the other one being "false risk" (one that is near a kitchen or some other place prone to accidental triggering)

The "false risk" smoke detectors should start the delay (and the local alarm)

This won't prevent unnecessary evacuation of the building, but it would prevent, or at least reduce, drawing the fire department away from actual emergencies, as well as possible bills to the building owner for false alarms should they be unable to catch the prankster or it was an accidental trip of a smoke detector or a problem with the system made it trigger for no reason.

Since the alarm still sounds regardless of whether the fire department gets called or not, this would pose no real danger to occupants. Assuming everyone in the building (or at least someone who can "herd" them out) knows what the alarm means (which shouldn't be too hard, because in addition to bells, buzzers or "shriekers" many have strobe lights with the word "fire") they would all get out before they were in any real danger.
-- Dickcheney6, Jun 04 2011

So, to summarize a little - a fire arm which gives some time in which to cancel false alarms?

Our system at work has this. If an alarm is triggered, it sounds an intermittent bell for some period, during which one of the fire-officers hares around the place to find the source of the alarm and decide if it's genuine or a false alarm (or something genuine but trivial). I know this because I've set off the alarm in my lab a couple of times. If the alarm continues un-cancelled for a certain period, it becomes a continuous bell and the fire brigade is called out.

Its main purpose is to prevent call-outs for trivial things (like smoke from an over-heated hotplate) causing call-outs, for which we end up paying some sort of fine.
-- MaxwellBuchanan, Jun 04 2011


That's exactly it! I guess that would make this baked then? whoops :)
-- Dickcheney6, Jun 05 2011



random, halfbakery