Temperature is easily measured using a
thermometer. Nowadays, thermometers come
in all shapes and sizes. In computer-based
automated process control applications, where
it may be required to control the temperature
of a plant, it is necessary to interface the
thermometer to the computer. This is usually
done either by using analogue temperature
sensor devices (such as thermistors,
thermocouples, RTD devices etc) and then
converting the outputs into digital format
using A/D converters, or digital sensors (such
as semiconductor sensor chips) are used with
direct interface to the computer’s.