A sensor is a device that detects physical parameters as input from the environment and responds accordingly.
It converts that physical parameter (for example: temperature, blood pressure, humidity, speed, etc.) into a signal which can be measured electrically (gives voltage). The specific input could be moisture, motion, light, pressure, heat etc.
We humans have 5 main senses that are vision, hearing, smell, touch and taste, our sensors include the eyes, ears, nose, skin and tongue respectively. As these sensors communicate with our mind and let us know all the things, Similarly like this electronic sensor communicates with microcontroller or microprocessor.
A sensor is a device that converts a physical quantity into electrical quantity. Physical quantities like pressure, temperature, force etc.
The output of the sensor is converted into human-readable value and displayed on screens and can be recorded in a database for further processing.
Before we proceed further you should know the difference between the sensors and transducers.
The main difference between sensor and transducer is that a transducer is a device which converts energy from one form to another, while sensor is a device which detects a physical quantity and converts the data into an electrical signal. Sensors are also a type of transducers.
There are two types of sensors
- Analog and
The sensors that produce continuous analog output signal these are considered as analog sensors. There are various types of analog sensors such as temperature, moisture, accelerometer, pressure, light, sound sensor etc.
Sensors in which data conversion & transmission takes place digitally are known as digital sensors.
In digital sensors, the signal measured is converted into digital signal by the sensor itself. And this digital signal is transmitted through wire digitally. Somehow it overcomes the disadvantages of analog sensors.
Examples of digital sensors are IR, ultrasonic, float, moisture sensor etc.
Note: Few sensors were made particularly of digital types while few were made of analog types and many sensors can be used in digital and analog modes. So basically it depends on us in which mode we want to use them.
We can also convert analog readings into digital with the help of ADC (Analog to Digital) converter.
WORKING PRINCIPLE OF SENSOR
very helpfull article for my arduino training and for better knowledge..