2-2. Types of Sensors

Five sensory organs of human body such as ears which senses sound in the environment nose which senses smell in the environment and tongue which senses taste of any food atom that we eat skin which senses the hotness or coldness of other body and eyes which senses different colors seen from it in

The same way sensor is an electronic device which detects and responds to some type of input from the physical environment and converts this output signals to in human readable display now let’s have a look

 

What is a Sensor?

In general, 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 electrical signal to connected control systems.

 

You can easily understand this from following simple block diagram.

For example, in an automation system, the sensor is the most important equipment that provides an input to the programmable logic controller (PLC).

In daily life applications, commercial and industrial devices, the educational projects, different types of sensor are used with a specific role.

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 the different types of sensor as follows.

 

1. Temperature Sensor (온도 센서)

Temperature sensor uses to detect the temperature and heat energy and convert it into an electrical signal (in form of voltage or current).

There are several types of temperature sensor used.

• Thermometer
• Thermocouple
• 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 (압력 센서)

Pressure sensor is called Pressure Transducer or Pressure Transmitter or Piezometer.

A pressure sensor detects the pressure of air, gas, water and provides 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 sensor, resistive touch sensor are the best example of touch sensor.

 

It is used in industrial applications like switches for turn on/off light, remote control by the air conditioner (AC), door open/close operation, elevator, and robotics, smartphones, so on.

An oximeter is one of the best example 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 sensor. 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

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 light sensor.

• Photoresistor or Light Dependent Resistor (LDR)
• Photodiode
• Phototransistor

It is widely used in the solar system, automobile, agriculture sector (automatic sprinkler system), and electronic-based project device like Arduino.

 

7. Vibration Sensor

Sometimes, 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 acknowledgement if there is any hazardous activity.

 

In an industrial area such as gas and oil, food and beverage, mining, metalworking, paper, wind power, power generation, the vibration sensords are needed.

 

8. Humidity Sensor

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) system.

WS1 Pro is an example of the wireless humidity sensor.

 

9. Proximity Sensor (근접센서)

Proximity sensor can easily detect nearby objects without any physical touch. It is divided into different types like-

• Capacitive Proximity Sensor
• Inductive Proximity Sensor

It is widely used in smartphones, tablet computers, machines, robotic systems, roller coasters, etc.

 

10. Colour Sensor

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 the color sensor.

For colour painting and printing, cosmetic material, textile area, medical diagnosis, computer color monitor, and the 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-ray.

Also, it senses electromagnetic radiation like waves, cosmic radiation (sunlight).

Radiation sensor includes three different type.

• 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 vessel, container, water tank, fuel tank bin, etc for water level check.

 

13. Position Sensor

Position sensor determines the displacement and the position (like linear and rotational).

Basically, position sensor available in the 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 the 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

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. 

Gas or smoke sensor is divided into three parts.

• Optical Type Smoke Sensor
• Ionization Type Smoke Sensor
• Laser Type Smoke Sensor

Smoke sensor is used in plant, 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 an alarm system, natural gas plant, fire suppression system and Arduino based design fire detector project.

 

16. Leak Sensor

Leak sensor is used in a closed vessel or vaccum 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

17. Accelerometer (가속도계)

Accelerometer is an instrument that measure motion acceleration or velocity.

It is used in many applications such as hand gesture controlled robot, navigation system for aircraft and missiles, process and control system, vehicle acceleration, and other rotating electronic equipment like a turbine, roller, fan, compressor, pump.

 

18. Tilt Sensor

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, and aircraft, etc.

 

19. Mark Sensor

Mark sensor works as photoelectric type of sensor. It is used to sense colour mark on presence of an objects.

Mark sensor is widely used in 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 area, power generating instruments, power plant, etc.

 

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