Patent ID: 9465012
Filing Date: 2016-10-11
CPC Classification: G01N

Claim Text:
1. A method for measurement of a change in environment at a sensor, the method including the step of providing the sensor having: a first layer formed of a piezoelectric material; a second layer formed adjacent the first layer and acoustically coupled with the first layer; and electrodes disposed to apply a driving signal to the first layer to generate bulk acoustic waves, wherein a temperature coefficient of frequency of the first layer is different to that of the second layer, the method further including the steps: detecting a first layer resonant frequency associated with the first layer and a combination resonant frequency associated with a combination of the first and second layers; detecting a shift in one or both of the first layer resonant frequency and the combination resonant frequency; identifying a portion of the shift caused by a temperature change at the sensor; and identifying another portion of the shift caused by an environmental change at the sensor other than the temperature change.