Sensors Sensors convert a physical parameter into an electrical signal, which may then be used as informational input into a process or display. Some parameters which may be sensed are listed below along with the type of transducer used for detection. A note on nomenclature. We see the words sensor, transducer, and element used together from time to time, and should clarify their meanings here.
Transducers change some measureable parameter, like energy or force, into some other parameter.
A photocell changes light intensity into electrical resistance, which can then be measured and acted upon by a circuit. A loudspeaker changes electrical waveforms into acoustic waveforms. They are both transducers. In industry they would use the term element to identify the photocell per se , and sensor for the whole package. At SAIC, we use a lot of raw transducers and build our own conditioning circuits to bridge the element into the rest of the art piece.