Perimeter motion sensors are an important aspect of any home security system and can be installed inside and outside. A perimeter motion sensor can make your home and your entire property more secure, but can also be customized to function intelligently, allowing you to save resources and energy. Essentially, there are two main types of detectors: the microwave and the Passive InfraRed. Microwave detectors transmit electromagnetic signals and recognize moving objects by comparing reflected and transmitted signals. Passive InfraRed sensors tend to provide better protection, however, because they detect movement against the background radiation levels, and have a much lower frequency of false alarms.

Products Available

Perimeter motion sensors can be simple or complex, depending on the make and model you choose to purchase. The Weatherproof Infrared detector is one of the best reviewed sensors, and can cover up to 165 feet. It is resistant to frost, snow, fog, and rain, which makes it perfect for all seasons. The machine is capable of automatically adjusting the trigger sensitivity level depending on the weather conditions. Some reviewers complained about the difficult of the initial set up, but there were no problems with the performance or effectiveness of the system. If money isn’t an issue, you can’t go wrong with the Optex iSeries Wireless Photoelectric Motion Detector. It is ideal for large areas and doesn’t need trenching, which drastically reduces the initial installation cost. It also comes with an environmental compensation circuit which reduces the potential for false alarms caused by ice, rain, fog, and snow. If you prefer a microwave system, try Southwest Microwave’s Rapid Deployment Sensors, which are perfect for outdoor environments. They can be relocated and are resistant to most weather conditions and temperatures. They are ideal for construction sites and freight yards, but can also be used for residential purposes, especially if you have a large property.

Pros & Cons

There are several advantages of owning perimeter motion sensors. For starters, they add extra security to your home and property. They can detect when intruders or unwanted visitors have entered your property line or home. If you have a large property in the woods or in a rural area, they can also detect unwanted wildlife. This can help you prevent rabbits or deer from destroying your lawn or garden, but also protect yourself from bears and wolves, depending on where you live. Some sensors can also detect rapid changes in temperature and other conditions, allowing to you to make the necessary adjustments. Perimeter motion sensors can be overly sensitive at times, however. This can lead to false alarms, which can be annoying in the middle of the night when you have to wake up and turn off the machine.

Motion sensor on a white background.

Example of Perimeter Motion sensor

Price Range

Perimeter motion sensors range in price from relatively inexpensive to very expensive. The Optex iSeries Wireless Photoelectric Motion Detector, for example, costs between $750 and $1000, although it is one of the most popular products on the market. The Weatherproof Infrared model is much more affordable at only $80, although it lacks some of the features found on the Optex.