Patent ID: 11959797
Assignee: BEIJING TAIFANG TECHNOLOGY CO., LTD.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 4:
5. The piezoelectric device online detection apparatus according to claim 1, wherein the control chip further comprises a calibration module which is configured to obtain a calibration coefficient according to the self-check result and correct the contact pressure according to the calibration coefficient;
when the self-check signal is less than a reference value, a capacitance of the elastic wave sensor is obtained through a following formula: f=α×c+β, wherein f is a frequency of the self-check signal, c is the capacitance of the elastic wave sensor, α and β are constants; and
a corrected contact pressure is calculated and obtained according to the capacitance of the elastic wave sensor, the contact pressure, and the calibration coefficient through a calibration function which comprises: P=P1+x−y×c, wherein P is the corrected contact pressure, P1 is the contact pressure obtained by the control chip according to the detection signal, c is the capacitance of the elastic wave sensor, and x and y are preset calibration coefficients, which are constants.