Sensors and their Signal Conditioning for Dynamic Acceleration, Force, Pressure, and Sound Applications

Abstract

The continued demand for efficiency, reliability, and lower operating costs together with the general increase in awareness of the effects of vibration and noise in the workplace has demanded a better understanding of the causes and characteristics of the vibration of machines and structures in many industries. This, coupled with advances in transducer technology, electronics, and signal processing power, has led to a wealth of commercial products for performing structural dynamics measurements.

Structural dynamics is the response of a structural system to dynamically imposed loads. Undesirable responses can cause suboptimum performance or structural failure. Understanding the relationships between forces and responses may involve in-service operational measurements or the creation of simulated environments in the laboratory. Analytical modeling verified by experimental modal analysis is a frequently employed tool to understand and/or adjust structural dynamics before the introduction of a product into service.

Successful testing depends on the accurate measurement of the dynamic force and pressure loading encountered by the structure as well as the response of the structure. The common electromechanical transducers that are used for these measurements are pressure transducers and microphones, load cells or force transducers, strain gages, and accelerometers. The signals from these devices are amplified and filtered in a way that preserves their fidelity over the required bandwidth and amplitude levels. Proper use depends on wise selection, informed by the knowledge of the required data and the limitations of the products. This chapter provides a guide to the sensing technologies and electronics available to make these measurements and their use.