Patent ID: 11137306

Abstract:
The disclosure relates to a method for monitoring the operation of a pressure measuring cell of a capacitive pressure sensor, wherein the pressure measuring cell comprises a pressure-dependent measuring capacitor and a pressure-dependent reference capacitor and the pressure measuring value is obtained as a measuring signal from the capacitance values of the measuring capacitor and the reference capacitor, wherein the measuring signal is supplied to an evaluation unit in the form of an alternating square-wave signal, the pulse height of the signal depending on quotients of the capacitance values of the reference capacitor and the measuring capacitor and the period of the signal being determined by the capacitance value of the measuring capacitor such that, in the nominal pressure range of the pressure sensor, there is a fixed correlation between the pulse height and the period, wherein the pairs of values of pulse height and period (h1, d1), . . . , (hn, dn) are stored as nominal values in an adjustment procedure for determined pressure values p1, . . . , pn, and wherein, for the currently measured pressure value px, with the pair of actual values (hx-IST, dx-IST), the pair of nominal values (hx-SOLL, dx-SOLL) is determined, and if there is significant deviation between the pair of actual values and the pair of nominal values, an error signal is generated.