Displacement Instrumentation

Abstract

Displacement is one of the basic and most widely measured quantities in the industry. The displacement sensed may be linear or angular. Different methods are in vogue — overlapping in nature vis-à-vis range and characteristics [Beckwith Buck and Marangoni, Donati Falzoni and Merlo, Neubert]. With each potential application, we have a choice and trade-offs. Applications, which require the displacement to be sensed directly, are as common as those, which use displacement sensing indirectly. In the latter case, the displacement is used as a measure of another physical variable, Strain and related quantities are often sensed in this manner. These are dealt with in subsequent chapters; here we restrict ourselves to sensing of displacement and quantities directly related to displacement.