ABSTRACT
The aspects for valid measurement are the transducer, the structure of the measuring system, and the system dynamics. This chapter examines the interaction between a transducer and its environment. It describes physical laws in sensing, static characteristics, modeling of transducers, and errors and uncertainties in measurements. Transducers are classified as self-generating or non-self-generating. These are examined in this section by means of the information model, energy model, incremental model, and generalized model. A transducer is potentially a multi-input, multi-output device. For the information model, only the signals (information) at the input and output are considered. Noise and loading in the sensing process are ignored. The guidepost for in-service calibration is that a known input will give a known output. The corollary is that a zero input will produce a zero output. The output for zero input is from the inherent noise in the instrument and it gives a datum for the measurement.
