If you need to keep your hard-earned possessions safe from an increasingly dangerous outside world, there’s nothing quite like a motion detector alarm to fit the bill. Though previous renditions of the technology were clunky, awkward, and unreliable through reliance on limited ultrasonic methodology, the new standard in passive infrared allows any alarm a great deal of accuracy and flexibility to detect only potentially hostile entities while filtering out all the background noise. The more and more streamlined exterior structures of such devices keep your security system non-obtrusive to you while you go about your life, and also renders them invisible to burglars… until the alarm has already gone off and intimidated the criminal into fleeing, that is.
Modern, up to date motion detection systems work through what is commonly abbreviated as a PIR (or Passive InfraRed) sensor. This technology allows them to safely and constantly detect motion based on the changes in atmospheric temperature. For example, any human body has a very constant and consistent temperature in a human-shaped size that the alarm will detect. Why is it called ‘motion’ detection instead of heat detection, you ask? Because the alarms have filters to screen out stationary or mostly stationary heated objects. That way, your fireplace or furnace won’t trip a false positive on the alarm. Only bodies of heat that move at human levels of speed cause the alarm to sound. The plastic that houses the actual alarm system can be passed through freely by infrared, while the housing protects the interior from dust, insects, and other minor interference.
Besides being able to distinguish moving objects from motionless ones, passive infrared alarms can also distinguish small bodies of heat from large bodies. If you have a dog or cat that roams the house, you can freely turn your alarm system on without having to worry about the pet triggering it. Any good alarm system worth money will only go off when it detects a human-sized presence in the environment, rendering the presence of animals and the like moot. Until burglars start training dogs to fetch stolen goods, it’s a non-issue!
The one significant limitation to passive infrared systems is that they have great difficulty passing through glass. However, since most of us don’t have rooms with walls of solid glass in our homes, it’s not an issue for the average person. Commonly, all this restriction means is that a person who owns a greenhouse can’t use a single infrared alarm for both the exterior and the interior. That minor issue aside, there are no major problems with infrared systems, which are trusted enough to be the standard in protection for not just private homes, but also for businesses and even government and military buildings. don’t gamble with your home’s safety; get an infrared motion detector before the dice roll snake eyes on your belongings.
