Aerotech QNP3 Series, Руководство по оборудованию

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Piezo Engineering Tutorial QNP3 Hardware Manual
Figure C-8: Example accuracy error calculated from the measurement data shown in Figure C-7
Figure C-9: Illustration showing how linearity is calculated based on measurement data taken
from a 100 μm piezo nanopositioning stage
C.4.2 Resolution
Resolution is defined as the smallest detectable mechanical displacement of a piezo nanopositioning stage.
Many piezo stage manufacturers will state that the resolution of a piezo actuator is theoretically unlimited
because even the smallest change in electric field will cause some mechanical expansion (or contraction) of
the piezo stack. Although theoretically true, this fact is largely impractical because all piezo actuators and
stages are used with electronics and sensors that produce some amount of noise. The noise in these
devices generally rises with increasing measurement sensor bandwidth. As a result, the resolution (or noise)
of a piezo nanopositioner is a function of the sensor bandwidth of the feedback device. Aerotech’s piezo
amplifiers and feedback electronics have been optimized to provide low noise and high resolution making
them suitable for some of the most demanding performance applications.
54 Appendix C www.aerotech.com