Question

A piezoelectric accelerometer has a transfer function of 60 mv/g and natural frequency of oscillation as 4.5 kHz . In a vibration test at 110 Hz a reading of 3.6 V peak results what is the magnitude of peak displacement in mm?
(correct up to 2 decimal places)

• A. 1.23

Answer 1

The correct option is A 1.23
$\text{Given sensitivity = 60 mv/g}$

$\text{Test frequency = 110 Hz}$

$\text{Max voltage = 3.6 volts peak}$

$\therefore \text{Max acceleration}=\frac{3.6}{60mv/g}$

$\text{Max acceleration = 60 g}$

$now,g=9.8/m/s^2$

$\therefore \text{Max acceleration}=60\times 9.81$

$=588.6m/s^2$

$\text{and max displacemet amplitude}=\frac{\text{Max Acceleration}}{{\omega }^2}$
$(\omega =2\pi f)$

$\therefore \text{displacement(max)}=\frac{588.6}{4{\pi }^2\times {110}^2}$

$=1.23\times {10}^{-3}$

$=1.23mm$