What is a Sensor Technology? Various Types of Sensors and their Applications

What is a Sensor? Various Types of Sensors and their Applications

We live in a Globe of Sensors. You can find various kinds of Sensors in our homes, workplaces, cars and so on. functioning to earn our lives easier by switching on the lights by spotting our presence, changing the room temperature, spot smoke or terminate, make us tasty coffee, open up garage doors as quickly as our car is close to the door and many various other jobs.

Sensor Technology

All these and many various other automation jobs are feasible because of Sensors. Before entering to the information of What is a Sensor, What are the Various Kinds of Sensors and Applications of these various kinds of Sensors, we'll first have a look at a simple instance of an automatic system, which is feasible because of Sensors (and many various other elements as well).

Real Time Application of Sensors

The instance we are discussing here's the Auto-pilot System in airplanes. Nearly all private and military airplanes have the feature of Automated Trip Control system or sometimes called as Auto-pilot.

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An Automated Trip Control System is composed of several sensors for various jobs such as speed control, elevation monitoring, position monitoring, condition of doors, challenge discovery, fuel degree, maneuvering and a lot more. A Computer system takes information from all these sensors and processes them by contrasting them with pre-designed worths.

The computer system after that provides control indicates to various components such as engines, flaps, rudders, electric motors and so on. that help in a smooth trip. The mix of Sensors, Computer systems and Auto technicians makes it feasible to run the airaircraft in Auto-pilot Setting.

All the specifications i.e., the Sensors (which give inputs to the computers), the computer systems (the minds of the system) and the auto technicians (the outcomes of the system such as engines and electric motors) are equally important in building an effective automated system.

This is an incredibly streamlined variation of Trip Control System. In truth, there are numerous individual control systems which preform unique jobs for a risk-free and smooth trip.

But in this tutorial, we'll be focusing on the Sensors component of a system and appearance at various ideas associated with Sensors (such as kinds, qualities, classification and so on.).

What is a Sensor?

There are many meanings as to what a sensor is but I would certainly prefer to specify a Sensor as an input device which provides an outcome (indicate) relative to a specific physical amount (input).

The call "input device" in the meaning of a Sensor means that it belongs to a larger system which provides input to a primary control system (such as a Cpu or a Microcontroller).

Another unique meaning of a Sensor is as complies with: It's a gadget that transforms indicates from one power domain name to electric domain name. The meaning of the Sensor can be better comprehended if we take an instance into factor to consider.

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The easiest instance of a sensor is an LDR or a Light Reliant Resistor. It's a gadget, whose resistance differs inning accordance with strength of light it's subjected to. When the light dropping on an LDR is more, its resistance becomes very much less when the light is much less, well, the resistance of the LDR becomes very high.

We can connect this LDR in a voltage divider (together with various other resistor) and inspect the voltage drop throughout the LDR. This voltage can be calibrated for light dropping on the LDR. Hence, a Light Sensor.

Since we have seen what a sensor is, we'll continue further with the classification of Sensors.

Classification of Sensors

There are several categories of sensors made by various writers and experts. Some are very simple, and some are very complex. The following classification of sensors may currently be used by a professional in the topic, but this is an extremely simple classification of sensors.

In the first classification of the sensors, they are split into Energetic and Easy. Energetic Sensors are those which require an outside excitation indicate or a power indicate.

Easy Sensors, on the various other hand, don't require any external power indicate and straight generates output reaction.

The various other type of classification is based upon the means of discovery used in the sensor. Some of the means of discovery are Electrical, Organic, Chemical, Radioactive and so on.

The next classification is based upon conversion sensation i.e., the input and the output. Some of the common conversion phenomena are Photoelectric, Thermoelectric, Electrochemical, Electro-magnetic, Thermooptic, and so on.

The last classification of the sensors are Analog and Electronic Sensors. Analog Sensors produce an analog output i.e., a continuous output indicate (usually voltage but sometimes various other amounts such as Resistance and so on.) relative to the amount being measured.

Electronic Sensors, as opposed to Analog Sensors, deal with distinct or electronic information. The information in electronic sensors, which is used for conversion and transmission, is electronic in nature.

Various Types of Sensors

The following is a listing of various kinds of sensors that are commonly used in various applications. All these sensors are used for measuring among the physical residential or commercial homes such as Temperature, Resistance, Capacitance, Conduction, Heat Move and so on.

  1. Temperature Sensor
  2. Distance Sensor
  3. Accelerometer
  4. IR Sensor (Infrared Sensor)
  5. Pressure Sensor
  6. Light Sensor
  7. Ultrasonic Sensor
  8. Smoke, Gas and Alcohol Sensor
  9. Touch Sensor
  10. Color Sensor
  11. Humidity Sensor
  12. Position Sensor
  13. Magnetic Sensor (Hall Effect Sensor)
  14. Microphone (Sound Sensor)
  15. Tilt Sensor
  16. Flow and Degree Sensor
  17. PIR Sensor
  18. Touch Sensor
  19. Strain and Weight Sensor

Temperature Sensor

Among one of the most common and most popular sensors is the Temperature Sensor. A Temperature Sensor, as the name recommends, detects the temperature i.e., it measures the changes in the temperature.


There are various kinds of Temperature Sensors such as Temperature Sensor ICs (such as LM35, DS18B20), Thermistors, Thermocouples, RTD (Resisting Temperature Devices), and so on.

Temperature Sensors can be analog or electronic. In an Analog Temperature Sensor, the changes in the Temperature represent change in its physical property such as resistance or voltage. LM35 is a classic Analog Temperature Sensor.

Coming to the Electronic Temperature Sensor, the output is a distinct electronic worth (usually, some numerical information after transforming analog worth to electronic worth). DS18B20 is a simple Electronic Temperature Sensor.

Temperature Sensors are used everywhere such as computer systems, smart phones, vehicles, air conditioning systems, markets and so on.

Distance Sensors

A Distance Sensor is a non-contact type sensor that spots the presence of an object. Distance Sensors can be executed using various methods such as Optical (such as Infrared or Laser), Sound (Ultrasonic), Magnetic (Hall Effect), Capacitive, and so on.

Some of the applications of Distance Sensors are Mobile Phones, Cars (Parking Sensors), markets (object alignment), Ground Distance in Airplanes, and so on.


Infrared Sensor (IR Sensor)

IR Sensors or Infrared Sensor are light centered sensor that are used in various applications such as Distance and Object Discovery. IR Sensors are used as distance sensors in nearly all smart phones.


There are 2 kinds of Infrared or IR Sensors: Transmissive Type and Reflective Type. In Transmissive Type IR Sensor, the IR Transmitter (usually an IR LED) and the IR Detector (usually a Picture Diode) are positioned facing each various other so that when an object passes in between them, the sensor spots the object.

The various other type of IR Sensor is a Reflective Type IR Sensor. In this, the transmitter and the detector are positioned beside each various other facing the object. When an object comes before the sensor, the infrared light from the IR Transmitter is reflected from the object and is detected by the IR Receiver and thus the sensor spots the object.

Various applications where IR Sensor is executed are Mobile Phones, Robotics, Commercial setting up, vehicles and so on.

Ultrasonic Sensor

An Ultrasonic Sensor is a non-contact type device that can be used to measure range as well as speed of an object. An Ultrasonic Sensor works based upon the residential or commercial homes of the acoustic waves with regularity higher than that of the human distinct range.


Using the moment of trip of the sound wave, an Ultrasonic Sensor can measure the range of the object (just like SONAR). The Doppler Shift property of the sound wave is used to measure the speed of an object.

Light Sensor

Sometimes also known as Picture Sensors, Light Sensors are among the important sensors. A simple Light Sensor available today is the Light Reliant Resistor or LDR. The property of LDR is that its resistance is inversely symmetrical to the strength of the ambient light i.e., when the strength of light increases, its resistance reduces and vise-versa.

By using LDR is a circuit, we can calibrate the changes in its resistance to measure the strength of Light. There are 2 various other Light Sensors (or Picture Sensors) which are often used in complex digital system design. They are Picture Diode and Picture Transistor. All these are Analog Sensors.


There are also Electronic Light Sensors such as BH1750, TSL2561, and so on., which can determine strength of light and provide an electronic equivalent worth.

Smoke and Gas Sensors

Among the very useful sensors in safety related applications are Smoke and Gas Sensors. Nearly all workplaces and markets are equipped with several smoke detectors, which spot any smoke (because of terminate) and sound an alarm system.

Gas Sensors are more common in labs, large range kitchen areas and markets. They can spot various gases such as LPG, Lp, Butane, Methane (CH4), and so on.


Now-a-days, smoke sensors (which often can spot smoke as well gas) are also installed in most homes as a security measure.

The "MQ" collection of sensors are a lot of inexpensive sensors for spotting CO, CO2, CH4, Alcohol, Lp, Butane, LPG and so on. You can use these sensors to develop your own Smoke Sensor Application.

Alcohol Sensor

As the name recommends, an Alcohol Sensor spots alcohol. Usually, alcohol sensors are used in breathalyzer devices, which determine whether an individual is intoxicated or otherwise. Police workers uses breathalyzers to capture drunk-and-drive offenders.


Touch Sensor

We don't give a lot importance to touch sensors but they became an essential component of our life. Whether you know or otherwise, all touch screen devices (Mobile Phones, Tablet computers, Laptop computers, and so on.) have touch sensors in them. Another common application of touch sensor is trackpads in our laptop computers.

Touch Sensors, as the name recommends, spot touch of a finger or a stylus pen. Often touch sensors are classified right into Resisting and Capacitive type. Nearly all modern touch sensors are of Capacitive Kinds as they are more accurate and have better indicate to sound proportion.


Colour Sensor

A Color Sensor is a useful device in building color noticing applications in the area of picture processing, color recognition, commercial object monitoring and so on. The TCS3200 is a simple Color Sensor, which can spot any color and output a settle wave symmetrical to the wavelength of the detected color.


Humidity Sensor

If you see Weather Monitoring Systems, they often provide temperature as well as humidity information. So, measuring moisture is an important job in many applications and Moisture Sensors help us in accomplishing this.


Often all moisture sensors measure family member moisture (a proportion of sprinkle content in air to maximum potential of air to hold sprinkle). Since family member moisture depends on temperature of air, nearly all Moisture Sensors can also measure Temperature.

Humidity Sensors are classified right into Capacitive Type, Resisting Type and Thermal Conductive Type. DHT11 and DHT22 are 2 of the often-used Moisture Sensors in DIY Community (the previous is a resisting type while the last is capacitive type).

Tilt Sensor

Often used to spot disposition or orientation, Tilt Sensors are among the easiest and affordable sensors out there. Formerly, turn sensors are comprised of Mercury (and hence they are sometimes called as Mercury Switches) but most modern turn sensors include a roller sphere.


In this article, we have seen about What Is a Sensor, what are the classification of sensors and Various Kinds of Sensors together with their practical applications. In the future, I will upgrade this article with more sensors and their applications.