sensor
An electronic device used to measure a physical
quantity such as temperature, pressure or loudness and convert
it into an electronic signal of some kind (e.g a voltage).
Sensors are normally components of some larger electronic
system such as a computer control and/or measurement system.
Analog sensors most often produce a voltage proportional to
the measured quantity. The signal must be converted to
digital form with a {ADC} before the CPU can process it.
Digital sensors most often use serial communication such as
{EIA-232} to return information directly to the controller or
computer through a {serial port}.
(1997-04-15)