Motion sensors are any such devices that are designed to sense motion and alert someone. These might seem useful only for security reasons, but they are more common than you think. You’ve probably heard a musical “ding-dong” when entering a liquor store or have stuck your hand between two closing elevator doors to watch the doors open up again. These are commonplace locations that utilize motion detectors to do what you barely notice every day.
There are several ways motion sensors detect movement. One way is through a beam of light that runs across a space near an opening. When that beam is broken, such as when a person walks through it, a sensor takes note of the change in light and rings a bell. Most stores will also have doors that automatically open when a person steps close. This is managed through a box above the door that sends out a burst of radio waves. These waves bounce back and the box senses it and notes how long the waves took to come back. When a person walks under the box, he disrupts the path of the waves and the box will notice the waves are arriving back faster and will open the door.
For most security systems, infrared energy is the preferred sensing method. These sensors are sensitive to the temperature of the healthy human body, which is about 93°F. These sensors also look for rapid change in temperature and infrared energy, meaning it won’t notify you when a sudden rain cools your pavement.
BK Electric has years of experience in installing motion sensors of every model and sensor type. Our installations are, of course, always up to code and done so with a permit, if one is required. Motion sensors can be installed by the homeowner, but we recommend consulting us, because it is easy to overload a circuit or suffer a mishap when dealing with electricity.