How Do Motion Sensors Work?

A motion sensor

Have you ever been walking down a dark hallway when suddenly a light turns on? While it could have been a friend playing a trick on you, it was most likely just a motion sensor light that was triggered by your movement. There are few different types of motion sensors. The one that works best for your household will depend on several factors.

Types of Motion Sensors

The three types of motion sensors commonly found for light fixtures include active sensors, passive infrared sensors, and dual-tech sensors. Each one of these sensors can be installed in or around a house, but some might be better suited depending on the homeowner’s lifestyle. Let’s examine each of these sensors and the kind of benefits and drawbacks they bring.

Active Sensors

These are the most common sensors used in households. Active sensors use radar waves and infrared energy to detect changes in the room they cover. Once this change is picked up the sensor activates and will trigger a switch for a light to turn on. Within active sensors, there are three categories:

  • ultrasonic
  • microwave
  • tomographic

Ultrasonic is the most popular type of active sensor as it’s used in the majority of motion sensing light fixtures. Meanwhile, microwave and tomographic sensors are used for security camera footage and other commercial uses. While these types of active sensors could be more efficient in detecting movement, they’re also more prone to distorted activations. This is due to the sensor’s ability to pick up even the tiniest of movement, like a microscopic bug in the room.

Passive Infrared Sensors

Passive infrared sensors are most used in wildlife cameras outside. This is because these types of sensors use infrared technology to detect heat, so they can pick up on large game animals like deer, elk, and boar. Most passive infrared sensors come with the ability to program the sensor so that it only detects a certain amount of heat. This can help from smaller animals like a pet dog or squirrel activating a sensor. Another reason passive infrared sensors are usually not used for household lighting is due to the limited area the sensor can cover. It’s usually a directional sensor that faces one way and is only activated by body heat being emitted in that position. This makes motion detection for lighting rather challenging. However, these sensors can be used for home security lights. Like wildlife cameras, these sensors could detect the body heat of a thief and shine a very bight light on them in the dead of the night.

Dual-Tech Sensors

These hybrid-type sensors are a combination of active and passive infrared sensors. The mechanics of a dual-tech sensor only work when both the active and passive infrared sensors pick up on movement and body heat. This allows for a very effective sensor that rarely ever turns on for something minor and insignificant. Dual sensors are mostly used in rooms that have a high occupancy of people like conference rooms, classrooms, or any smaller auditoriums. This is because dual-tech sensors tend to meet the requirements of a few bodies entering the room at one time.

Finding the Right Sensor

Motion sensors can make life a lot easier. These cool uses of modern technology cut out the middleman. Whether you’re a forgetful person and tend to leave lights on when you leave, or you’re just tired of making the trip to the other side of the room to turn a light off, simplistic solutions like 3-way switches and motion sensors are the way to go. Your situation and the number of people in your household have a lot to do with the type of sensor that best fits your need. At Lightning Bug Electric our team would be happy to help assess your situation and lead you towards the best option for a motion-detecting light fixture.

For more information on motion sensors and how they could change your household, feel free to contact our team of certified electricians today!

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