Sensors and its applications
In this post, you are going to learn about what is a sensor? some practical examples of a sensor, classification of sensors, different types of sensors, Real-time applications of sensors.
We live in a world of sensors. You can find different types of sensors in our homes, offices, vehicles, mobiles etc. With the help of these sensors we making our lives easier by turning lights and fans by detecting our presence, adjusting the room temperature, detect smoke or fire, make us delicious coffee, open garage doors as soon as our car is near the door and many other tasks.
All these and many automation are possible because of sensors.
What is a sensor?
There are different definitions are there. The technical definitions of a sensor are as follows:
Sensor a device, module or subsystem which detects or measures a physical property and records, indicates, or otherwise responds to some type of input from the physical environment. The specific input could be light, heat, motion, moisture, pressure, or any one of a great number of other environmental phenomena. The output is generally a signal that is converted to human-readable display at the sensor location or transmitted electronically over a network for reading or further processing.
The sensor is a device, module, or subsystem whose purpose is to detect events or changes in its environment and send the information to other electronics, frequently a computer processor. A sensor is always used with other electronics, whether as simple as a light or as complex as a computer.
It is a device that converts signals from one energy domain to electrical domain.
We can simply say sensor as an input device (means that it is a part of a bigger system) which provides input to the main control system (like a processor or a Microcontroller) and which provides an output (signal) with respect to a specific physical quantity (input).
A good sensor obeys following rules;
- It is sensitive to the measured property.
- It is insensitive to any other property likely to be encountered in its application, and
- It does not influence the measured property.
Examples:
Here are few examples of different types of sensors
We can understand the definition of a sensor by seeing a real-life example:
Today technology is ruling the world. For example, if we take smartphones. It comprises of so many sensors.
Today’s smartphone contains following sensors:
- Proximity sensor
- Accelerometer
- Gyroscope
- Magnetometer
- Light sensor
- Barometer
- Thermometer
- Air humidity sensor
- Pedometer
- Fingerprint sensors
- Heart rate sensor
- Infrared (IR) blaster
- Iris scanner
Like that, so many sensors are there in different smart mobiles phones and with these sensor mobiles phones, we are making our life simple.
In a mercury-based glass thermometer, the input is temperature. the liquid contained expands and contrasts in response, causing the level to be higher or lower on the marked gauge, which is human readable.
An oxygen sensor in a car’s emission control system detects the gasoline/oxygen ratio, usually through a chemical reaction that generates a voltage. a computer in the engine reads the voltage and if the mixture is not optimal readjusts the balance.
Motion sensors in various systems including home security lights, automatic doors, and bathroom fixtures typically send out some type of energy, such as microwaves, ultrasonic waves or light beams and detect when the flow of energy is interrupted by something entering its path
A photosensor detects the presence of visible light, infrared transmission (ir), and ultraviolet (UV) energy.
Classification of sensors:
There are several classifications of sensors made by different authors and experts. Some are very simple and some are complex.
In the first classification of the sensors, they are divided into Active and Passive
Active sensors: active sensors are those which require an external excitation signal or a power signal.
Passive sensors: passive sensors` on the other hand, do not require any external power signal and directly generates output response.
The other type of classification is based on the means of detection used in the sensor. Some of the means of detection are electric, Biological, Chemical, Radioactive etc.
The other type of classification is based on the means of detection used in the sensor. some of the means of means of detection are photoelectric, thermoelectric, Electrochemical, Electromagnetic, thermos-optic, etc.
The final classification of the sensor is Analog and Digital Sensors. Analog Sensors produce an analog output i.e. a continuous output signal with respect to the quantity being measured.
Digital Sensors, in contrast to Analog sensors. Work with discrete or digital data. The data in digital sensors, which is used for conversion and transmission, is digital in nature.
Different types of sensors :
There are different types of sensors that are commonly used in various applications. All these sensors are used for measuring one of the physical properties like Temperature, Resistance, Capacitance, Conduction, Heat Transfer etc.
- Temperature sensor
- Proximity sensor
- Accelerometer
- IR sensor (infrared Sensor)
- Pressure sensor
- Light sensor
- Ultrasonic sensor
- Smoke, gas, and alcohol Sensor
- Touch sensor
- Color sensor
- Humidity sensor
- Tilt sensor
- Flow and level sensor
Real life applications of sensors:
There are so many applications of sensors in our day to day life.
We use mobiles phones which consists of so many sensors.
If we go some shopping malls doors are automatically open by sensing moving objects.
