Vibration and Acoustics Measurements in Rotating Machinery

In Chapters 3 and 4 , we studied various experimental methods to estimate unbalances and dynamic bearing parameters, respectively. These methods involve measurement of input (forces) and output (vibration responses) in the time domain. For subsequent processing, often these measurements are required in the frequency domain. In this chapter, we will describe the overall measurement and analysis systems. General terminology associated with measurement systems is presented. Methods of sensitivity analyses of parameters estimated because of errors involved in the measurements are presented. Various kinds of transducers (the conditioning, amplifying, and analyzing instruments) and vibration exciters are described, especially those that are suited for experimentations and measurements in rotating machinery. Transducers include displacement, velocity, acceleration, force, and acoustic transducers.