ABSTRACT
This chapter provides the development of signal acquisition and conditioning systems and derives a unified method for representing and upgrading the quality of instrumentation signals between sensors and data-conversion systems. It explores the additional signal quality improvement available by averaging redundant signal conditioning channels plus extension to analog signal processing. The chapter discribes input circuit noise, impedance, and grounding effects for signal conditioning optimization. It examines models that combine device and system elements for the evaluation and improvement of signal quality, expressed as total error, arising from the influence of random and coherent interference. External interference entering low-level instrumentation circuits frequently is substantial and techniques for its attenuation are essential. The goal of shield ground placement in all cases is to provide a barrier between signal cables and external interference from sensors to their amplifier inputs. Signal conditioning is concerned with upgrading the quality of a signal to the accuracy of interest coincident with signal acquisition, scaling, and band-limiting.
