chapter  36
Acceleration, Vibration, and Shock Measurement
Pages 34

Acceleration is an important parameter for general-purpose absolute motion measurements and vibration and shock sensing. Acceleration is measured accelerometers, which are commercially available in a wide variety, types, and shapes to meet the requirements of diverse range applications. œey are manufactured in small sizes, light in weight, rugged, and robust to be able to operate in harsh environment. œey can be conŸgured as active or passive sensors. An active accelerometer (e.g.,  piezoelectric) gives an output without the need for an external power supply, while a passive accelerometer only changes its electric properties (e.g., capacitance) and requires an external electrical

36.1 Accelerometer Dynamics: Frequency Response, Damping, Damping Ratio, and Linearity ......................................................36-3 Periodic Vibrations • Stationary Random Vibrations • Transients and Shocks • Nonstationary Random Vibrations

36.3 Piezoelectric Accelerometers ......................................................36-11 36.4 Piezoresistive Accelerometers .....................................................36-14 36.5 Di¥erential-Capacitance Accelerometers .................................36-14 36.6 Strain-Gage Accelerometers .......................................................36-17 36.7 Seismic Accelerometers ...............................................................36-17 36.8 Inertial Types, Cantilever, and Suspended-Mass

ConŸguration ................................................................................36-21 36.9 Electrostatic Force Feedback Accelerometers ..........................36-23 36.10 Microaccelerometers ....................................................................36-24

3D Accelerometers 36.11 Cross-Axis Sensitivity ..................................................................36-26 36.12 Selection, Full-Scale Range, and Overload Capability ...........36-27

Capability (Frequency Range): Sensitivity, Mass, and Dynamic Range ................................................................ 36-28 Transient Response • Full-Scale Range and Overload Capability • Environmental Conditions

Bibliography ..............................................................................................36-32 Partial List of Vendors and Suppliers .....................................................36-33

power source. In applications, the selection of active-or passive-type accelerometer is important, since active sensors cannot measure static or DC mode operations.In applications where static measurements are involved, passive sensors must be used. In general, accelerometers are preferred over displacement and velocity sensors for the following reasons:

1. œey have awide frequency range from zero tovery high values. Steady accelerations can easily be measured.