The Online Encyclopedia and Dictionary







A sensor is a technological device or biological organ that detects, or senses, a signal or physical condition and chemical compounds.


Artificial sensors

Most sensors are electrical or electronic, although other types exist. A sensor is a type of transducer. Sensors are either direct indicating (e.g. a mercury thermometer or electrical meter) or are paired with an indicator (perhaps indirectly through an analog to digital converter, a computer and a display) so that the value sensed becomes human readable. Aside from other applications, sensors are heavily used in medicine, industry and robotics.

Since a signal is a form of energy, sensors can be classified according to the type of energy they detect. For example:

Biological sensors

All living organisms contain biological sensors with functions similar to those of the mechanical devices described. Most of these are specialized cells that are sensitive to:

The human senses are examples of specialized neuronal sensors.

See also


Disambiguation note for the orthographically challenged

A sensor is not to be confused with:

  • censor, a person who decides what can be published
  • censor, an ancient Roman political office
  • censer, a utensil for incense

Last updated: 06-02-2005 13:54:18
Last updated: 08-25-2005 00:27:44