In 1950, Samuel Bango invented the first motion sensor and named it the burglar alarm. Based on the principles of ‘The Doppler Effect,’ he used the basics of quantum radar technology and ultrasonic waves. Today, most motion sensors use Samuel Bango’s device principles. 

Motion sensors are one of the popular types of IoT sensors. They can be incorporated with popular devices and applications in industries and smart homes. They have a vast use case, including security systems, lighting, and more. Motion sensors are a simple yet effective medium for efficiently gathering valuable data.

Table of Contents:

What is a Motion Sensor?

A motion sensor is an electronic device that uses sensors to detect the slightest motion of objects or people very precisely. Motion sensors are the backbone of any security system. When a motion sensor detects any motion, it sends an alert to a dedicated security system.

With the technology available today, you can set it up in a way that sends an alert to your phone or the monitoring team. Not only with security systems but motion sensors can also be used in home appliance control and automated lighting control with motion sensor lights to be more energy efficient. Motion sensors can react to changes in motion indoors, in living rooms, cameras, and windows. With the availability of smart lights, motion sensors can now a part of your home automation solutions.

Motion sensors can be used in:

  • Security systems for homes, banks, offices, shopping malls, and industries.
  • Preventing people from intruding into the restricted areas.
  • Saving energy by giving power to the smart lights when required.

Motion Sensor types

There are various ranges of motion sensors available in the market, each with different powers, advantages, and disadvantages. The most popular ones are Passive Infrared sensors (PIR), Microwave sensors, Ultrasonic sensors, Tomographic motion sensors, and Dual-Technology motion sensors.

Passive Infrared motion sensor (PIR)

Passive Infrared motion sensors are the most common motion sensors used in home and office security systems. They are small, easy to use, low-powered, and inexpensive. These sensors can detect motion by sensing temperature changes between an object or people and the background.

A passive infrared motion sensor has a pyroelectric film that detects and reacts to infrared radiation. All warm-blooded animals, including humans, produce Infrared radiation. 

The PIR motion sensor camera has two small sensors. When everything is idle, the PIR sensor camera detects ambient infrared radiation from the background. When a human or warm-blooded animal passes by the sensor, it can detect the heat signature change in both sensors and send an alert to the security system.

Microwave motion sensor

Microwave motion sensor emits microwave radiation continuously. These microwave pulses catch moving object reflections. Above all, these microwaves send high radio frequencies and calculate the reflection of objects or people by detecting shifts in frequency. When it detects the frequency shift, the motion detector gets activated. 

These sensors cover larger areas than PIR sensors can. However, Microwave sensors are vulnerable to object and electrical inferences. Sometimes, It can cause false alarms. This motion sensor is expensive and consumes a lot of power. 

Ultrasonic motion sensor

Active Ultrasonic motion sensors generate ultrasonic sound waves that bounce off the moving objects and determine the reflection of the ultrasonic sound waves. After receiving the signal, the motion sensor calculates the distance between the sensor and the moving target by measuring the duration between emitting and receiving the signal. On the other hand, passive ultrasonic motion sensors can only able to detect specific movements.

Most active ultrasonic motion sensors allow users to configure their sensitivity and adjust the range. These types of motion sensors are expensive, susceptible, and prone to false alarms. Humans do not hear Ultrasonic sound waves, but animals like fish, cats, and dogs can. Therefore, it might be distressful to them.

Tomographic motion sensor

Tomographic motion sensors are a network of multiple nodes that generate radio waves. They can detect any movement when an object or person breaks the connection between two nodes with their presence. These sensors can detect objects and walls. They are costly and primarily used in storage units, warehouses, factories, and other places to provide security.

Dual Technology Motion Sensor

Dual Technology motion sensors are based on a technology that uses both Passive Infrared motion sensors and microwave motion sensors. These motion sensors are used primarily for reducing the chance of false alarms. However, there is a drawback to these kinds of motion sensors. 

Dual Technology motion sensors only activate when both microwave and passive infrared sensors sense motion. Though this reduces the chances of false alarms, you can miss accurate alerts by using this motion sensor.

Difference between Indoor and Outdoor motion sensors

Motion sensor and motion sensor lights are the primary part of the security system on Techavo Systems
Motion sensors are the primary part of the security system

Indoor motion detection sensors:
Indoor motion detection sensors detect motion within the home. Passive infrared (PIR) motion sensors are the most common sensors, usually used in a home. These sensors can be used for security systems, lighting, and energy efficiency.

Outdoor motion detection sensors:
Outdoor motion detection sensors are used outdoors. People mostly avoid Passive Infrared motion sensors outdoors as they can be tampered with by the heat. Outdoor motion detection sensors tend to be waterproof to withstand weather difficulties.
Duel Technology motion sensors are mainly used in outdoor security systems. People can adjust the frequency of these sensors to avoid false alarms. 

What can be paired with motion sensors in homes?

Due to technological advancements, installing a motion sensor is very easy. Pairing with automation devices allows you to activate the motion sensors easily. You can easily pair your wireless motion sensor with smart plugs, smart light switches, smart bulbs, etc. With these products, you can manage the lights in your home.

When the motion sensor bulb or motion sensor LED light detects any movement, it automatically turns on. This is good news for homeowners who are still searching for light switches on the wall in the dark.

You can even pair motion sensors with smart security cameras. When the sensor detects any kind of movement, it starts recording. With smart home applications and controlling devices, managing motion sensor devices has never been this easy.

Where should I place the motion sensors?

When you are thinking about placing the motion sensors, you need to think deeply about what actions you need to detect. If you are using the motion sensor for security purposes, you should place the motion sensor-enabled devices near the entry points of your home.

These blend well with home decor, books, vases, and other items. You should avoid a few places for motion sensors. Placing motion sensors near heat or radiation can trigger false alarms. 

What should be considered while using motion sensors?

Here are a few points you need to remember before placing the motion sensors in your home:

  • Adjust the frequency of the sensors so they cannot be falsely triggered by your pet.
  • Maintain a certain height.
  • Make sure unwanted objects do not block the sensor.
  • Motion sensors are sensitive towards heat. So, place the motion sensor accordingly.


Motion sensors are an integral part of security systems and automation solutions. In this article, we discussed what a motion sensor is. We briefly described popular motion detection sensor types, such as Passive Infrared sensors (PIR), Microwave sensors, Ultrasonic sensors, Tomographic sensors, and Dual-Technology motion sensors. 

We also provided information regarding what pairs best with motion detection sensors and the difference between indoor and outdoor motion sensors. The guide also contains tips on a few things to remember while integrating a motion detection sensor.


Q. What uses a motion sensor?
A: Motion sensors mainly assist in security systems for homeowners and industries. They detect the motion of objects and people to alert managers. In addition, motion sensors can automatically turn on or off the lights or open doors when a person is near the sensor.

Q. Why do we need motion sensors?
A: Motion sensors are an integral part of security systems. They warn owners of unauthorized movement at homes and businesses. Multiple types of motion sensors can be beneficial for your home and business.

Q. Which sensor is best for motion detection?
A: There are several types of motion sensors available in the market. Passive Infrared sensors work great at detecting human and animal movements. They are easy to use, small, and inexpensive. The chances of false alarms are low on PIR motion sensors in small areas.

Q. Are motion sensors cameras?
A: No, motion sensors are not cameras. However, they are widely used in security cameras. This technology detects any kind of motion near the device by reading heat signatures through infrared radiation, ultrasonic waves, microwaves, and others.

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Abhijit Roy Content Writer
Abhijit Roy is your next-door writer who has experience in the Esports industry, B2B tech and jotting down complex topics into engaging reads. This Veteran writer loves to share his opinion about every tech video he watched last night.