A review of sensor sensitivity and stability

Acoustic sensor sensitivity is often reported in units of Hz per unit of measurand. It has been frequently stated or implied in the sensor literature that higher-frequency sensors are preferable to lower frequency sensors because the frequency change per unit of measurand is higher, i.e., the higher-frequency sensors are more "sensitive". This paper reviews the resonator instabilities that lead to the conclusions that: 1) sensitivity expressed as Hz per unit of measurand is not a good measure of sensor quality, and 2) when compared on the bases of accuracy, reproducibility and resolution capability, "good" low frequency sensors are often superior to "good" high frequency ones.