What is a Sensor? How Do They Work?

by | Mar 22, 2023

sensor is a device that detects and responds to physical input. The specific input could be light, heat, motion, moisture, pressure, or any of a variety of other environmental phenomena. The output is typically a signal that is converted to a human-readable display at the sensor location or electronically transmitted over a network for reading or further processing.

We live in a Sensory World. Sensors can be found in our homes, offices, and cars, and they work to make our lives easier by turning on the lights when we walk in the room, adjusting the room temperature, detecting smoke or fire, making us delicious coffee, opening garage doors when our car approaches, and many other tasks.

Different Types of Sensors:

The following is a list of various sensor types that are commonly used in various applications. All of these sensors are used to measure physical properties such as temperature, resistance, capacitance, conduction, heat transfer, and so on.

  • 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
  • Position Sensor
  • Magnetic Sensor (Hall Effect Sensor)
  • Microphone (Sound Sensor)
  • Tilt Sensor
  • Flow and Level Sensor
  • PIR Sensor
  • Touch Sensor
  • Strain and Weight Sensor

How do Sensors work?

Sensors are known to change their electrical properties in response to changing physical conditions. It has been discovered that most artificial sensors rely on electronic systems for analysing, capturing, and relaying environmental data.

In layman’s terms, a sensor converts stimuli such as sound, motion, heat, and light into electrical signals. These signals are routed through an interface, which converts them into binary code before sending them to a computer to be processed.

The sensors primarily function as switches, controlling the flow of electric charges through the circuit. Switches are essential components of electronics because they change the state of the circuit.

Semiconducting material is used in sensors’ components such as transistors, diodes, and integrated circuits or chips. These materials are incorporated into sensor circuits so that they can function as switches.

Sensors typically detect changes and objects in the environment by using radiation such as laser or light, infrared radio waves, or other waves such as ultrasonic ones. This is possible if they have a source of energy that helps them emit radiation in the direction of their target object.

This radiation is reflected back by the object and detected by the sensor; this type of sensor is known as an active sensor. Passive sensors do not emit their own radiation or waves, instead detecting what is emitted by the target objects such as thermal infrared radiation, heat, or radiation from external sources such as the Sun reflected off the objects.