Premises security (part 1) System Types
If any of you have had any experience with security alarms for your home or workplace, you will no doubt be aware that the control panel and sometimes a remote sounder or strobe light will often have batteries fitted to them.
These batteries are often rechargeable cells which are recharged while mains electricity is supplied to the control panel. In the event of power loss, these batteries should maintain the operation of the security system until power is restored.
There are a couple of points to consider here.
The first is that there is always a trade-off of cost & size vs functionality, risk and aesthetics.
What I mean by this is that the designers can EITHER make a very robust electronic security system which will run without an external power source, for days on end, and allow for the added demand of an attempted break-in while STILL preserving the integrity of the system.
OR
They can build a neat little wall mounted unit which has lots of electronic "features" ... and a small rechargeable battery "in-case-of" power failure.
For the first design, we probably wind up with a fairly bulky (large storage-capacity batteries are not known for their lightweight & compact design), and probably not a very sexy looking system, which costs a lot and takes a large site to install in.
These batteries are often rechargeable cells which are recharged while mains electricity is supplied to the control panel. In the event of power loss, these batteries should maintain the operation of the security system until power is restored.
There are a couple of points to consider here.
The first is that there is always a trade-off of cost & size vs functionality, risk and aesthetics.
What I mean by this is that the designers can EITHER make a very robust electronic security system which will run without an external power source, for days on end, and allow for the added demand of an attempted break-in while STILL preserving the integrity of the system.
OR
They can build a neat little wall mounted unit which has lots of electronic "features" ... and a small rechargeable battery "in-case-of" power failure.
For the first design, we probably wind up with a fairly bulky (large storage-capacity batteries are not known for their lightweight & compact design), and probably not a very sexy looking system, which costs a lot and takes a large site to install in.
For the second design, the opposite is true.
Small, sleek, easy to install almost anywhere, and doesn't cost anywhere near as much.
The down-side to this, is that in a planned intrusion (such as while you are on vacation), power can be removed from your premises sufficiently in advance to allow the system to become inoperative.
In the case of many of the smaller Do-It-Yourself security kits, the internal backup battery may only support the system for between 2 and 8 hours.
Fortunately, most electronic security panels now-a-days have some "intelligence" built into them!
At this point, I should digress long enough just to ensure that everyone understands that there are a number of basic types of security installation:
1. At the top of the scale you have the site which has full closed-circuit electronic video camera surveillance and perimeter intrusion detection, backed-up by on-site security guards monitoring the cameras and doing physical checks on a random basis.
Small, sleek, easy to install almost anywhere, and doesn't cost anywhere near as much.
The down-side to this, is that in a planned intrusion (such as while you are on vacation), power can be removed from your premises sufficiently in advance to allow the system to become inoperative.
In the case of many of the smaller Do-It-Yourself security kits, the internal backup battery may only support the system for between 2 and 8 hours.
Fortunately, most electronic security panels now-a-days have some "intelligence" built into them!
At this point, I should digress long enough just to ensure that everyone understands that there are a number of basic types of security installation:
1. At the top of the scale you have the site which has full closed-circuit electronic video camera surveillance and perimeter intrusion detection, backed-up by on-site security guards monitoring the cameras and doing physical checks on a random basis.
2. Next rung down might be the site which has full closed-circuit electronic video camera surveillance and perimeter intrusion detection being reported back to an off-site security monitoring center.
3. Down another rung the site might only have one or other of video or perimeter protection reported back to an off-site security monitoring center.
These first three examples are what is known as "monitored" or "back-to-base" security systems
4. Another step down might be the site which has full closed-circuit electronic video camera surveillance and perimeter intrusion detection, but no off-site monitoring, only a local siren and possibly a flashing strobe to draw attention.
4. Another step down might be the site which has full closed-circuit electronic video camera surveillance and perimeter intrusion detection, but no off-site monitoring, only a local siren and possibly a flashing strobe to draw attention.
5. Getting towards the bottom of the scale is the site which has only one or other of video or perimeter protection with no off-site monitoring. Perimeter-only detection probably being the most basic alarm system anyone would install
These latter two examples are what is known as "local alarm" systems.
With "local" systems, there are again several sub-categories.
1. You have the audible and/or visible deterrent type of system.
2. You have the video capture system where video security cameras record to digital data storage such as disk, DVD, or videotape.
While obviously there are many permutations of video vs perimeter, with/without physical site patrols/guards, local alerts vs monitored systems, for the purpose of this topic, suffice to say there are the two categories of Local vs Monitored systems
If your system is a "monitored" system, then when external power is lost, the unit may call the monitoring centre after a period of time. Failing this, when the battery nears exhaustion, a "battery low" warning may be sent to the control centre.
If your system is "local alarm", meaning there is no external monitoring, guess what happens ?
(Part 2)
Labels: alarm, camera, detection, home, intrusion, perimeter, security, surveillance, video capture, workplace
posted by Col. Sanders | 6:21 AM
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