The choice of a sensor for a specific application can be determinded by its transfer
characteristics. However, in many cases the choice of sensors is limited. Sensor
transfer characteristics are normally nonlinear, temperature-sensitive, have high
noise levels, requires span adjustment, and are offset from zero. The situation is
aggravated when precise measurements and a fast correction time are required. A
linear relationship is required between process variables and the output signal for
actuator control. In analog circuits, linearization is very hard to achieve and
requires the use of specialized networks.