I was semi-convinced that I'd left my television on this morning before leaving for work. This made me slightly paranoid that it would somehow set off the burglar alarm - I know that it detects movement, but would it register moving TV pictures as movement in the living room? Can't even remember why I had turned the telly on in the first place. Anyway, I suspect I was worrying about nothing, but in the same way as if I'd left the gas on (I don't even have gas!) I figured I'd better pop home during lunch to be on the safe side. Just as easy to eat sandwiches at home than at my work desk, and it's only a ten minute walk.
When I got back here, the alarm was not ringing. The TV was not on, and neither was the gas that I don't have. So that was ok, except that now I have an unanswered question: Can a TV set off a burglar alarm? I think I'm bordering on the "no", but I have no idea how motion detectors work so can't be sure. It'll keep. A nice experiment for a bored day. Maybe I'll try it on the same day as I use my dishwasher for the first time (it's been nearly a year and a half since I moved here now...).
Whilst I was home at lunch, I thought I may as well spend the time by waiting to see if a parcel arrived for me from Amazon. It didn't, but I think they had only posted it a few hours earlier so this wasn't too surprising.
Subscribe to:
Post Comments (Atom)
3 comments:
Most burglar alarms (but not necessarily all) work in the infra-red spectrum. They split their field of view into cells (easily done, the sensor works in the same way a composite fly eye does, it's made up of lots of smaller sensors, each covering their own little area of the total field of view), and if a heat source moves across a couple of these, the alarm is sounded. Most also have a "tolerance" level, to prevent things like the patch of carpet heated by the sun (which moves during the day) or random fluctuations in the sensors, from setting the thing off.
So, in short, no, a TV can't set off a burglar alarm. Unless you have some highly sophisticated (and fine grain) alarm sensors that work in the visual range.
An overzealous house-watcher once mistakenly set the alarm to "Away" instead of "stay" after checking on the dogs. The resulting dog movement caused at least 8 calls to an out of range cell phone, and one notification to the police department. They never investigated it further after no response, which leads me to believe that a serial killer could have been inside dancing about and the police wouldn't have known. Of course, there wasn't. Yet still....
You've never used your dishwasher?
So the alarm would have been safe then. That's good to know.
Stop Press: I have just now, for the first time ever put some things in the dishwasher and turned it on! I don't have any dishwasher soap, but I'm sure it'll be ok as a test. Sooooo exciting!
Post a Comment