A device that detects the changes in electrical or physical or other quantities and thereby produces an output as an acknowledgement of change in the quantity is called a Sensor. The most frequently used different types of sensors are classified based on the quantities such as Electric current or Potential or Magnetic or Radio sensors, Humidity sensor, Fluid velocity or flow sensors, pressure sensors, Thermal or Heat or Temperature sensors, Proximity sensors, Optical sensors, position sensors, Chemical sensor, Environment sensor, Magnetic switch sensor, etc.
- Sensors used for detecting the speed of an object or vehicle is called a Speed sensor.
- A device that gives temperature measurement as an electrical signal is called a temperature sensor.
- An electronic sensor used for measuring the infrared light radiation emitted from objects in its field of view is called a PIR sensor or Pyroelectric sensor.
Classification of Sensors
- Active and Passive Sensors:
Active sensors are the type of sensors that produces an output signal with the help of an external excitation supply. Passive sensors are the type of sensors that produces output signal without the help of external excitation supply.
- Analog and Digital Sensors:
The sensor that produces a continuous signal concerning time with analogue output is called Analog sensors. On the other hand, when data is converted and transmitted digitally, it is called Digital sensors.