If you have had any dealings at all with security systems for home or business, you are familiar with the concept of motion detection. A security system is generally made up of one motion detector sensor or even several sensors which comprise part of the system.
The device itself is electronic and it contains a sensor which may be mechanical in nature or electronic. The purpose of a motion detector sensor is to recognize if something is moving in the field of it’s view. Some sensors use an infra-red sensor and when the infrared beam is broken, the broken signal produces a signal. the signal is electronic and the entire device then makes a determination as to what to do with the signal. It may produce an audible alarm. The signal may set off a series of actions such as a phone call to an alarm monitoring station. The electronic signal may also start a video recording of some sort. Depending how you have set up your particular system, a video camera may do all of the above. I think the device has changed the way we view security in our country and I install them daily in my job as a Security Consultant and Installer.
I installed 3 motion detector sensors this week at our local bank inside of the vault. The motion sensors were part of a back-up system the bank wanted. If all else failed with the primary system, the back-up system would sound a loud audible alarm inside the bank if it detected motion inside the vault during certain hours. I also had it connected to a secret cell phone calling system that would automatically call the local police department.
Some motion detectors can sense body heat. these are called passive infrared sensors. Ultrasonic sensors are ones that send out energy pulses and these pulses reflect off an object. What happens is the sensor has the ability to measure the pulses and can detect a moving object. Of course, your local Police use a very familiar and universally hated motion sensor called the radar gun. Radar guns use microwave sensors. The radar detectors in your cars can detect the microwave signals and sets off your alarm. Your radar detector itself is sort of a motion detector also.
Motion detectors are part of our everyday life even if we do not notice them. Virtually every business that has a security system uses some form of motion detection. I make a living with them and they make us much safer.