Electronic technologies are rapidly growing. One of the things that really fascinate me that many of the electronic devices around us operate without human touch.
Just like humans, with evolving technology, we can sense the things and objects around us.
For this technology, the sensor plays an integral role to monitor and detect physical activities and providing information to other electronic devices.
Let’s start with the basics.
Table of Contents
What is a Sensor?
In general, the sensor is known as a Detector.
The basic definition of,
A sensor is an electronic equipment that is used to detect and observe the physical activities and pass the notifcation/signal to other electrical control devices.
In other words, a sensor is an electronic device that can transform energy from one form to another form. So, it is also called a Transducer.
The main function of the sensor is to identify and communicate with physical quantities such as temperature, heat, pressure, distance, moisture, gas, and so on.
And it provides output in the form of an electrical signal to connected control systems.
You can easily understand this by the following simplified block diagram.
For example, in an automation system, the sensor is the most important piece of equipment that provides input to the programmable logic controller (PLC).
In daily life applications, commercial and industrial devices, and educational projects, different types of sensors are used with a specific roles.
What are the different types of Sensors?
Sensors are split up into four main categories. Such as,
- Analog Sensor
- Digital Sensor
- Active Sensor
- Passive Sensor
Each category is having different types of sensors as follows.
1. Temperature Sensor
There are several types of temperature sensors used.
- Resistance Temperature Detector (RTD)
- Thermistor Temperature Sensor
- Semiconductor Temperature Sensor
- Vibrating Wire Temperature Sensor
The temperature sensor is used in a computer, refrigerator, automobile, medical device, cooking appliances, electrical motor, etc.
2. Pressure Sensor
The pressure sensor is called a Pressure Transducer or Pressure Transmitter or Piezometer.
A pressure sensor detects the pressure of air, gas, water and provides an electrical signal to the controller.
According to different uses and many more features, it is divided into different parts like,
- Vacuum Pressure Sensor
- Absolute Pressure Sensor
- Gauge Pressure Sensor
- Differential Pressure Sensor
Pressure sensors are used in many systems like pneumatic, hydraulic, vacuum systems, etc.
3. Touch Sensor
The touch sensor is called a Tactile sensor. It is an electronic sensor that is used for detecting and recording physical touch.
Capacitive touch sensors, resistive touch sensors are the best example of the touch sensor.
It is used in industrial applications like switches for turning on/off lights, remote control by the air conditioner (AC), door open/close operation, elevator, and robotics, smartphones, so on.
An oximeter is one of the best examples of a touch-based sensor to detect oxygen levels in the human body.
In this COVID pandemic, Pulse Oximeter is in huge demand. It is easy to handle and operate, even at your home. You can easily buy an online Pulse Oximeter.
4. Image Sensor
The image sensor is an electronic device that is used to detect the image pixels and provide information to the display devices.
There are analog and digital types of sensors. Generally, an electronic image sensor is classified into two main types.
- Charge-Coupled Device (CCD)
- Active Pixel Sensor
For the digital camera, closed-circuit television (CCTV), medical imaging equipment, thermal imaging devices, radar, sonar, etc., image sensors are used.
5. Motion Sensor
Motion sensor measures and records physical activities or movements. It is classified into different types.
- Active Motion Sensor
- Passive Motion Sensor
- Tomographic Motion Sensor
- Gesture Motion Sensor
The motion sensor is used in home security, automatic doors operation, microwaves, robotics, ultrasonic waves, gesture detector, etc.
6. Light Sensor
The light sensor is a photoelectric device. This sensor detects and converts the brightness or luminescence of light or photon into an electrical signal.
There are three types of the light sensor.
- A Photoresistor or Light Dependent Resistor (LDR)
It is widely used in the solar system, automobile, agriculture sector (automatic sprinkler system), and electronic-based project devices like Arduino.
7. Vibration Sensor
Sometimes, a vibration sensor is known as Piezoelectric Sensor.
The vibration sensor detects and records any movement or activities. And it provides data or signals to connected machines or systems.
This sensor helps to send acknowledgment if there is any hazardous activity.
In industrial areas such as gas and oil, food and beverage, mining, metalworking, paper, wind power, power generation, vibration sensors are needed.
8. Humidity Sensor
A humidity sensor is also known as a Hygrometer.
For detecting moisture in air and soil, the humidity sensor is very essential. Mostly, it is used in Air Conditioner (AC) systems.
WS1 Pro is an example of a wireless humidity sensor.
9. Proximity Sensor
A proximity sensor can easily detect nearby objects without any physical touch. It is divided into different types-
- Capacitive Proximity Sensor
- Inductive Proximity Sensor
It is widely used in smartphones, tablet computers, machines, robotic systems, roller coasters, etc. You will find many manufacturers of Proximity sensors, worldwide.
10. Colour Sensor
The Colour sensor is the type of photoelectric sensor.
It helps to sense the color of an object and recognize the color mark. This sensor uses RGB (red, green, and blue) color scale.
SEN-11195 is the best example of a color sensor.
For color painting and printing, cosmetic material, textile area, medical diagnosis, computer color monitor, and process control, colour sensor is used.
11. Radiation Sensor
A radiation sensor is an electronics instrument that senses and measures the radiation particles like alpha, beta, gamma, neutrons, X-rays.
Also, it senses electromagnetic radiation like waves, cosmic radiation (sunlight).
Radiation sensor includes three different types.
- Gas-filled Radiation Sensor
- Scintillation Radiation Sensor
- Solid-state Radiation Sensor
This sensor is used for nuclear energy, medical imaging modalities, and monitoring of environmental radioactivity.
12. Level Sensor
The main role of the level sensor is to measure the level or height of different materials like solid, liquid, and gaseous.
It is classified into different parts.
- Laser Level Sensor
- Float Sensor
- Capacitive Level Sensor
- Resistive Level Sensor
- Ultrasonic Level Sensor
- Hydrostatic Level Sensor
- Optical Level Sensor
- Electromagnetic Level Sensor
It is widely used in vessels, containers, water tanks, fuel tank bins, etc for water level checks.
13. Position Sensor
The position sensor determines the displacement and the position (like linear and rotational).
Basically, position sensors are available in different types.
- Optical Position Sensor
- Linear Position Sensor
- Rotary Position Sensor
- Inductive Position Sensor
- Capacitive Position Sensor
- Fiber-Optic Position Sensor
- Ultrasonic Position Sensor
For example, a potentiometer contains a rotational position sensor that can vary with angular movement.
The position sensor is used in domestic and industrial applications like door closing/opening, valve monitoring, motor controlling, throttles for controlling the flow of fuel or power to an engine.
14. Gas or Smoke Sensor
A gas sensor is used to detect different types of gasses, toxic or explosive gasses, smoke in the air. Some of these sensors are also capable to measure gas concentration.
The gas or smoke sensor is divided into three parts.
- Optical Type Smoke Sensor
- Ionization Type Smoke Sensor
- Laser Type Smoke Sensor
The smoke sensor is used in plants, industries, buildings, ships, airplanes, etc.
15. Flame Sensor
The flame sensor easily detects fire or flame of nearby materials. These detected signals are passed to the connected control devices.
It is used in industrial areas for alarm systems, natural gas plants, fire suppression systems, and Arduino-based design fire detector projects.
16. Leak Sensor
A leak sensor is used in a closed vessel or vacuum for detecting water leakage, fluid leakage, air leakage, etc.
As per the working role, it is divided into two main parts.
- Spot Leak Sensor
- Flow Leak Sensor
An accelerometer is an instrument that measures motion acceleration or velocity.
It is used in many applications such as hand gesture controlled robots, navigation systems for aircraft and missiles, process and control systems, vehicle acceleration, and other rotating electronic equipment like a turbine, roller, fan, compressor, pump.
18. Tilt Sensor
The tilt sensor detects and varies with an angular movement, angular slope, angular motion, axes of the reference plane.
It is mostly used for monitoring the angle and auto-rotating operation in mobile, tablet, hand-held games, boats, vehicles, aircraft, etc.
19. Mark Sensor
Mark sensor works as a photoelectric type of sensor. It is used to sense colour marks in the presence of objects.
Mark sensor is widely used in the printing and packaging industries.
20. Flow Sensor or Float Sensor
Flow sensor measures and detects virtually any process fluid. This detected data will be provided to the controller system.
It is used in industrial areas, power generating instruments, power plants, etc.
In this tutorial, I have covered 20 different types of sensors with their uses. Every sensor has its own features and functionalities. They can be used for a specific purpose.
For the handheld or wireless-based electrical and electronics project, various types of sensors are used.
Thanks for Reading!
I have completed master in Electrical Power System. I work and write technical tutorials on the PLC, MATLAB programming, and Electrical on DipsLab.com portal.
Sharing my knowledge on this blog makes me happy. And sometimes I delve in Python programming.