handbook of modern sensors

28 2 Sensor Characteristics
Fig. 2.10. Responses of sensors with different damping characteristics.
Fig. 2.11. Types of response: (A) unlimited upper and lower
frequencies; (B) first-order limited upper cutoff frequency; (C)
first-order limited lower cutoff frequency; (D) first-order limited
both upper and lower cutoff frequencies; (E) narrow bandwidth
response (resonant); (F) wide bandwidth with resonant.
Damping is the progressive reduction or suppression of the oscillation in the
sensor having higher than a first-order response. When the sensor’s response is as
fast as possible without overshoot, the response is said to be critically damped (Fig.
2.10). An underdamped response is when the overshoot occurs and the overdamped
response is slower than the critical response. The damping ratio is a number expressing
the quotient of the actual damping of a second-order linear transducer by its critical
damping.
For an oscillating response, as shown in Fig. 2.10, a damping factor is a measure
of damping, expressed (without sign) as the quotient of the greater by the lesser of
a pair of consecutive swings in opposite directions of the output signal, about an
ultimately steady-state value. Hence, the damping factor can be measured as
Damping factor = F A = A B = B = etc. (2.24)
C