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. In addition to other applications, sensors are heavily used in medicine, industry and robotics.
Excerpt - page 268: "... unexpected danger. The latest Doppler LIDAR (Laser-induced Doppler and ranging) sensors provide a first defense against ... When the laser beams hit airborneparticles such as dust or aerosols, they reflect back the laser ..."
Excerpt - page 141: "... are to them in special ways. Some species have heat sensors near their lips, which enable ... is also a sensor, carrying airborneparticles to a chemical analyser in the roof of its mouth; ..."
