sensor

noun

sen·​sor ˈsen-ˌsȯr  ˈsen(t)-sər 

1

: a device that responds to a physical stimulus (such as heat, light, sound, pressure, magnetism, or a particular motion) and transmits a resulting impulse (as for measurement or operating a control)

2

: sense organ

Did you know?

Sensors are used today almost everywhere. Radar guns bounce microwaves off moving cars. A burglar alarm may use a photosensor to detect when a beam of light has been broken, or may use ultrasonic sound waves that bounce off moving objects. Still other sensors may detect pressure (barometers) or chemicals (Breathalyzers and smoke detectors). Stud finders, used by carpenters to locate wooden studs under a wall, may employ magnets or radar. Wired gloves, which relay information about the position of the fingers, are used in virtual-reality environments. A cheap car alarm may be nothing but a shock sensor, in which a strong vibration will cause two metal surfaces to come together.

Synonyms

• detector

Examples of sensor in a Sentence

Image sensors are used in digital cameras.

Infrared sensors can track an object's movement.

Recent Examples on the Web

That big 41-megapixel sensor jutted forth from the phone body, and Nokia reps showed off its low-light, rapid-motion camera abilities by shooting pictures of breakdancers in a dark demonstration room. —Ars Technica, 17 Feb. 2025

The number of sensors used to record brain activity can vary from one to hundreds. —Paul McClure 16, New Atlas, 16 Feb. 2025

In driver-assist systems, a lidar sensor uses lasers to create a 3D map of a car’s surroundings. —Evelyn Cheng, CNBC, 16 Feb. 2025

One of its two detectors, named ARCA, was only operating at about 10 percent capacity when its sensors picked up the particle. —Sara Hashemi, Smithsonian Magazine, 14 Feb. 2025

Word History

Etymology

Latin sentire to perceive + English -or entry 1 — more at sense

First Known Use

circa 1928, in the meaning defined at sense 1

Kids Definition

sensor

noun

sen·​sor ˈsen-ˌsȯ(ə)r 

ˈsen(t)-sər

: a device that detects a physical quantity (as a movement or a beam of light) and responds by transmitting a signal

Medical Definition

sensor

noun

sen·​sor ˈsen-ˌsȯ(ə)r  ˈsen(t)-sər 

: a device that responds to a physical stimulus (as heat, light, sound, pressure, magnetism, or a particular motion) and transmits a resulting impulse (as for measurement or operating a control)

also : sense organ