sensor

SEN-ser /ˈsen.sər/
nounB2SATACTTOEFLIELTS
technicalgeneral

A device that detects or measures a physical property (such as heat, light, sound, pressure, magnetism, or motion) and records, indicates, or otherwise responds to it.

Acts as the sensory organ of a machine. It bridges the physical world and the digital world by converting physical phenomena into electrical signals.

The story behind the word. Derived from the Latin sentire, meaning 'to feel' or 'to perceive'. While humans have sensory organs, the modern spelling and technical meaning of 'sensor' emerged in the early 20th century to describe electrical devices that 'feel' physical changes.

Word relationships

  • detector: A detector simply reveals the presence of something (e.g., a smoke detector), whereas a sensor often measures the exact quantity or intensity of a physical property.
  • transducer: A transducer is the technical term for any device converting energy from one form to another; a sensor is a transducer that specifically converts physical energy into an electrical signal.
  • actuator: An actuator converts electrical signals into physical movement, whereas a sensor converts physical phenomena into electrical signals.

Commonly confused with

  • indicator: An indicator merely displays a state visually (like a litmus paper strip), while a sensor active measures and transmits data to a control system.

Word family

  • sensory (adjective): Relating to sensation or the physical senses.
  • sensory-motor (adjective): Relating to both sensory and motor activity.

Collocations

  • motion sensor
  • temperature sensor
  • optical sensor
  • sensor array

Example sentences

  • "The thermostat uses a motion sensor to detect when a room is occupied and adjusts the temperature accordingly." A description of smart home technology.
  • "Modern cars are equipped with proximity sensors in the bumpers to assist drivers with parking." An automotive safety review.

Memory hook

A sensor helps a robot 'sense' its surroundings, just like your eyes and ears help you. Sensor = Senses the world.

When not to use

Avoid using for purely mechanical indicators that do not transmit data or trigger a response, such as a simple glass thermometer (which is an indicator, not a modern sensor).

Fun facts

  • The whiskers on robotic cats and dogs are actually sophisticated touch sensors designed to mimic the navigation aids of real animals.

Related words

telemetry, haptic

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