subject: Types Of Outdoor Security Systems [print this page] Home Security systems can be broken down into two main categories indoor systems and outdoor security systems. In the following article I will take a look at the various types of outdoor security systems and explain the physics of concepts of how the security systems work. I will specifically be looking at the following types of outdoor home security systems: Vibration Sensors, Magnetic Field Detection, E-Field, Microwave Barriers, Microphonic Systems, Taut Wire Fence Systems, Fibre Optic Cable, H-Field
Passive Infared Systems/Detectors
PIR or Passive Infrared Detectors are one of the most common types of detectors found in small business and house security systems. Passive referring to the fact that the systems does not need external energy to function. Passive Infared Detectors function by begin able to tell when there is a change in the temperature in a giving zone, it accomplishes this by first measuring the static temperature of a zone then monitors the space for a change in temperature.
Ultrasonic Detectors
Ultrasonic systems work on the physics of sound. These systems admit ultra sonic sound that in undetectable by humans. Ultrasonic systems work on the Doppler shift and can detect movement by a change in the frequency. Take in mind that these types of systems are considered obsolete by many security companies and are not regularly used.
Microwave Systems
Microwave alarm systems work by emitting microwaves from a transmitter and measures reflections and beam intensity using a receiver. Microwave alarm systems are often combined with a PIR detector to reduce false alarms.
Photo-Electric Beams
Photo-electric alarm systems transmit either visible or infrared beams across an area, setting a so called tripwire, and when the beams are obstructed it will trigger an alarm system. You may remember these as depicted in many spy or action movies.
Glass Break Detectors
Glass break detector used for internal perimeter building protection. These systems are triggered when a glass window or door is broken. These systems detect the breaking glass through acoustic waves or shock frequencies.
