For a definition shown, click on the alphabet and the word of your choice, or enter a keyword in the "search word" then enter. This glossary will be updated regularly with new definitions.
A sensor is an electronic device for detecting or measuring a physical stimulus. Cameras have light sensors and elevators are equipped with presence sensors to prevent the doors from closing when someone is there. In biometrics, sensors are integrated with software for such purposes as capturing and analysing the outline of the hand in hand geometry applications.
Sensors are indispensable for computers or other electronic devices to interact with the outside world. A sensor is what acquires the image, of say a retina or a fingerprint, needed by the biometrics system for analysis. The image can obtained by an optical sensor with the help of a miniature camera, by a capacitive sensor that detects the weak electrical charges created by the pressure of the finger, for instance, or by an ultrasound sensor that detects tiny differences in reverberation on the surface of an object. Anti-metal detector frames in airports are equipped with sensors that detect disturbances in magnetic fields.