Measurement uncertainty

The is the first of two chapters covering the subject of measurement uncertainty. Chapter 3 introduces the two main types of measurement error, systematic and random, and discusses the typical sources of both of these error types. The various techniques available for reducing the magnitude of systematic errors are then considered. This is followed by a discussion on the means available for quantifying any remaining systemic errors that remain after all procedures to reduce their magnitude have been followed. This chapter concludes with a discussion on the induced noise that often corrupts the electrical output signals from measurement sensors and transducers. Such induced noise arises both within the measurement circuit itself and also during the transmission of measurement signals to remote points. Ways of designing measurement systems such that induced noise is minimized are discussed. However, it is noted that elimination of all such noise is difficult, and signal processing (as discussed in Chapter 8) has to be applied to deal with any noise that remains.