What is sensor? - Definition from WhatIs.com
Part of the Electronics glossary:

A sensor is a device that detects and 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. 

Here are a few examples of the many different types of sensors:

In a mercury-based glass thermometer, the input is temperature. The liquid contained expands and contracts 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/or ultraviolet (UV) energy.

 

This was last updated in July 2012
Contributor(s): Ivy Wigmore
Posted by: Margaret Rouse

Related Terms

Definitions

  • modulation

    - Modulation is the process of adding information to a steady waveform or to an electronic or optical carrier signal, usually applied to electromagnetic signals. (SearchNetworking.com)

  • resistance

    - Resistance is the opposition that a substance offers to the flow of electric current; the term contrasts with conductance, which is a measure of the ease with which current flows through a substance. (WhatIs.com)

  • electric field strength

    - Electric field strength is a quantitative expression of the intensity of an electric field at a particular location. (WhatIs.com)

Glossaries

  • Electronics

    - Terms related to electronics, including definitions about electrical components and words and phrases about computers, laptops parts, digital cameras, televisions and home appliances.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question. Find an Answer.Powered by ITKnowledgeExchange.com

Ask An IT Question

Get answers from your peers on your most technical challenges

Ask Question

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.