Electronic technology is rapidly developing. One thing that excites me the most is: many electronic devices around us operate without human supervision.
With the advancement of technology, we have created many sensors that can perceive the surrounding environment.Sensors play an indispensable role in monitoring and detecting human activities, providing this information to other electronic devices as control references.
Next, let’s start with the basics, here is the table of contents for today’s discussion.
01
What Types of Sensors Are There?
1. Temperature Sensor
2. Pressure Sensor
3. Touch Sensor
4. Image Sensor
5. Motion Sensor
6. Light Sensor
7. Vibration Sensor
8. Humidity Sensor
9. Proximity Sensor
10. Color Sensor
11. Radiation Sensor
12. Level Sensor
13. Position Sensor
14. Smoke or Gas Sensor
15. Flame Sensor
16. Leak Sensor
17. Accelerometer
18. Tilt Sensor
19. Mark Sensor
20. Flow Sensor or Float Sensor
02
What is a Sensor?
Generally, a sensor is basically defined as a detector; a sensor is an electronic device used to detect various categories of signals and transmit them to other electrical control devices.
In other words, a sensor is an electronic device that can convert energy from one form to another. Hence, it is called a sensor.
Sensors primarily identify physical quantities such as gas, heat, etc., through distance, temperature, humidity, etc. It provides output in the form of electrical signals to the connected control system.
For example, in automated systems, sensors transmit signals to programmable logic controllers (PLC), thereby participating in control. Different types of sensors play specific roles in daily applications, commercial and industrial equipment, and educational engineering.
03
What Are the Different Types of Sensors?
Sensors are divided into four main categories:
1. Analog Sensors
2. Digital Sensors
3. Active Sensors
4. Passive Sensors
Each category has different types of sensors.
1. Temperature Sensor
The temperature sensor is used to detect temperature and thermal energy and convert it into electrical signals (transmitted in the form of voltage or current).
We actually have several types of temperature sensors in use.
1. Thermometer
2. Thermocouple
3. Resistance Temperature Detector
4. Thermistor Temperature Sensor
5. Semiconductor Temperature Sensor
6. Vibrating Wire Temperature Sensor
Temperature sensors are commonly found in devices such as computers, refrigerators, cars, medical equipment, cooking appliances, etc.
2. Pressure Sensor
The pressure sensor can also be referred to as a pressure transmitter or pressure gauge.
The pressure sensor detects the pressure of air, gas, and water and provides electrical signals to the controller.
Depending on different uses and more characteristics, it is classified into different categories:
1. Vacuum Pressure Sensor
2. Absolute Pressure Sensor
3. Gauge Pressure Sensor
4. Differential Pressure Sensor
Pressure sensors are used in many systems, commonly in pneumatic, hydraulic, and vacuum systems.
3. Touch Sensor
The touch sensor, also known as a tactile sensor, is an electronic sensor used to detect and record human touch.
Capacitive touch sensors and resistive touch sensors are the most commonly used types of touch sensors.
Industrially, they are widely used in applications such as light switches, air conditioning (AC) remote controls, door operations, elevators, robots, smartphones, etc.
Interestingly, a pulse oximeter is one of the best examples of a touch sensor used to detect the oxygen content in the human body.
During this pandemic, the demand for pulse oximeters has significantly increased. They are easy to operate, even at home. You can easily purchase a pulse oximeter online.
4. Image Sensor
The image sensor is an electronic device used to detect image pixels and provide information to display devices.
Image sensors can be analog or digital. Generally, electronic image sensors are divided into two main types.
1. Charge-Coupled Device
2. Active Pixel Sensor
Image sensors are used in digital cameras, closed-circuit television (CCTV), medical imaging devices, thermal imaging devices, radar, sonar, etc.
5. Motion Sensor
The motion sensor measures and records body activity or movement. It is classified into the following types.
1. Active Motion Sensor
2. Passive Motion Sensor
3. Tomographic Motion Sensor
4. Gesture Motion Sensor
Motion sensors are used in home security, automatic door operations, microwaves, robotics, ultrasound, gesture detection, etc.
6. Light Sensor
The light sensor is a photoelectric device that detects and converts the brightness or luminescence of light or photons into electrical signals.
Currently, there are mainly three types of light sensors in use.
1. Photoresistor or Light Dependent Resistor (LDR)
2. Photodiode
3. Phototransistor
It is widely used in solar-powered cars, agricultural sectors (automatic sprinkler systems), and electronic project devices such as Arduino.
7. Vibration Sensor
The vibration sensor may not be widely known, but it is also referred to as a piezoelectric sensor.
The vibration sensor can detect and record any motion or activity. It provides data or signals to connected machines or systems.If any hazardous activity is present, the sensor helps send confirmation information.
In our industries such as oil and gas, food and beverage, mining, metal processing, paper making, wind power generation, and electricity generation, vibration sensors are required.
8. Humidity Sensor
The humidity sensor, also known as a hygrometer;
is essential for detecting moisture in the air and soil. It is mainly used in air conditioning systems.
9. Proximity Sensor
The proximity sensor can easily detect nearby objects without any direct contact. It is classified into different types:
1. Capacitive Proximity Sensor
2. Inductive Proximity Sensor
It is widely used in smartphones, tablets, machines, robotic systems, roller coasters, etc.
10. Color Sensor
The color sensor is essentially a photoelectric sensor. It helps perceive the color of objects and identify color markings. This sensor uses RGB (Red, Green, Blue) color codes.
Color sensors are widely used in our painting and printing, cosmetics, textiles, medical diagnostics, computer color monitors, and process control.
11. Radiation Sensor
The radiation sensor is an electronic instrument that can sense and measure radiation particles such as α, β, γ, neutrons, and X-rays.
Additionally, it can sense electromagnetic radiation such as waves and cosmic radiation (sunlight).
The radiation sensor includes three different types.
1. Gas-Filled Radiation Sensor
2. Scintillation Radiation Sensor
3. Solid-State Radiation Sensor
This sensor is used in nuclear energy, medical imaging modes, and environmental radioactive monitoring, so we generally do not often see this type of sensor in our daily lives, but it is actually closely related.
12. Level Sensor
The main function of the level sensor is to measure the level or height of different materials such as solids, liquids, and gases.
It is classified into the following types:
1. Laser Level Sensor
2. Float Sensor
3. Capacitive Level Sensor
4. Resistive Level Sensor
5. Ultrasonic Level Sensor
6. Hydrostatic Level Sensor
7. Optical Level Sensor
8. Electromagnetic Level Sensor
Level sensors are widely used in ships, containers, water tanks, fuel tanks, etc., for water level checks.
13. Position Sensor
The position sensor determines the displacement and position (such as linear and rotational).
Essentially, position sensors are divided into several types.
1. Optical Position Sensor
2. Linear Position Sensor
3. Rotational Position Sensor
4. Inductive Position Sensor
5. Capacitive Position Sensor
6. Fiber Optic Position Sensor
7. Ultrasonic Position Sensor
For example, a potentiometer contains a rotational position sensor that changes with angular movement,
Position sensors are widely used in home and industrial applications, such as door closure/opening, valve monitoring, motor control, and throttle control for engine fuel or power flow.
14. Smoke or Gas Sensor
The gas sensor is used to detect different types of gases, toxic or explosive gases, and smoke in the air. Some of these sensors can also measure gas concentration.
Gas or smoke sensors can be divided into three major categories:
1. Optical Smoke Sensor
2. Ionization Smoke Sensor
3. Laser Smoke Sensor
Smoke sensors are used in factories, industries, buildings, ships, aircraft, etc.
15. Flame Sensor
The flame sensor can easily detect fire or flames from nearby materials. The detected signals are transmitted to the connected control device.
It is used in alarm systems in industrial areas, natural gas plants, fire extinguishing systems, and Arduino-based fire detection projects.
16. Leak Sensor
The leak sensor is used in sealed containers or vacuum chambers to detect water leaks, liquid leaks, air leaks, etc.
It is divided into two main parts based on working roles:
1. Point Leak Sensor
2. Flow Leak Sensor
17. Accelerometer
An accelerometer is an instrument used to measure motion acceleration or speed.
It is widely used in gesture-controlled robots, aircraft and missile navigation systems, process control systems, vehicle acceleration, and other rotating electronic devices such as turbines, rollers, fans, compressors, pumps, etc.
18. Tilt Sensor
The tilt sensor detects angular motion, angular tilt, and changes in the axis of the reference plane. It is mainly used in monitoring angles and automatic rotation operations for devices like mobile phones, tablets, handheld gaming consoles, ships, vehicles, aircraft, etc.
19. Mark Sensor
The mark sensor works as a photoelectric sensor. It is used to sense color markings on objects. The mark sensor is widely used in the printing and packaging industry.
20. Flow Sensor or Float Sensor
The flow sensor measures and detects almost all process fluids. The detected data will be provided to the control system.
It is used in industrial fields, power generation instruments, power plants, etc.
In this article, I introduced 20 different types of sensors and their uses. Each sensor has its own characteristics and functions. They can be used for specific projects, such as the increasingly popular handheld or wireless electronic engineering, which use various types of wireless sensors.
Additionally, sensors are also used in PLC projects, robotic systems, Internet of Things (IoT) projects, etc.
Source: Automation Technology by Gongkong Lao Zhou, copyright belongs to the original author. If there are any copyright issues regarding the work, please contact us for deletion in a timely manner. Thank you!
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