Self-generating sensors convert energy for a particular domain to another. The output signal, in this case, turns out to be zero since the signal itself is the only energy applied. For this reason, the sensor is referred to the as self-generating transducer. Self-generating transducers have no output and hence there is no offset as depicted in figure 1 below (Langereis, 1999). This aspect the reason for choosing the thermocouple sensors. Only the slope needs to be known.
.This group of sensors refers to transducers consisting of devices into which energy could be applied by a specific source. The energy is then modulated using a chemical or physical parameter. Typical examples include the Pt-100 thermo-resistive temperature sensors and pH sensing ISFET. In the case of these sensors, it is possible to eliminate the offset through measuring of the output based on another element that is hardly sensitive to this measured parameter (Kissinger, Hart, & Adams, 1973). In this regard, a zero output would imply that all the conditions in the measuring device equal the conditions at the other device (Langereis, 1999). The choice of these sensors is thus based on the possibility to eliminate undesired signals such as unstable references. The Wheatstone bridge shown below is the most applicable differential set-up in case.
.The sensor-actuator system is one of the commonest causes of integrated systems and may involve a smart use of data obtained using several sensors. While a typical integration may involve the joining of various structures, it can also involve the integration in data interpretation.