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

In simpler terms, the sensors capture information about how the individual bands react to wavelengths cast on them, which helps determine the material content of the item. —Meghan Hall, Sourcing Journal, 23 Jan. 2025

Beyond having a user input everything manually, sensors are the most effective way to get this data. —Jennifer Pattison Tuohy, The Verge, 22 Jan. 2025

One obstacle to the more widespread use of these futuristic firefighting tools, including sensors that can detect smoke and fire, is a dearth of private and public sector funding. —Queenie Wong, Los Angeles Times, 21 Jan. 2025

The thermocouple sensor detects the heat from the pilot light and sends a signal to keep the gas valve open, but if the pilot light is extinguished, then the thermocouple will send a signal to the gas valve to stop the flow of gas to the pilot light. —Timothy Dale, Better Homes & Gardens, 19 Jan. 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