Читать книгу Vibrations of Linear Piezostructures - Andrew J. Kurdila - Страница 18

Among all the various categories of applications of piezoelectric devices and systems, it is perhaps the piezoelectric sensors that have had the most profound impact on measurement technology infrastructure. As noted above, there are a wide and growing collection of piezoelectric transducers that serve as sensors. These include pressure transducers, load cells or force transducers, torque transducers, acoustic microphones, accelerometers, and vibration sensors. The underlying physical basis of nearly all these sensors is the same: the forces applied on opposite sides of a piezoelectric specimen generate a source of charge that is highly sensitive to the applied force, and the measurement of the charge or current provides an estimate of such forces over extremely high frequencies. Often the bandwidth of such sensors extends to the hundreds of kilohertz range. The diversity of piezoelectrically‐based, commercial microphones available from PCB® is illustrated in Figure 1.7. This figure illustrates that the operating range of these sensors is as high as O(100) kHz, and their sensitivity varies from O(1) mV/Pa to O(10) mV/Pa. The physics underlying a wide range of piezoelectric sensors is studied in Chapters 3, 4, 5, 6, 7, and 8.