Method for self-monitoring of capacitive ceramic pressure measuring cell of capacitive pressure sensor for measuring process pressure of e.g. oil, involves producing error signal when measurement values deviate from each other

摘要

The method involves obtaining a main measurement value using a ratio of reference capacitance and measuring capacitance of a capacitive ceramic pressure measuring cell (10). The main measurement value is evaluated based on process pressure. A control measurement value is obtained based on the process pressure. A frequency of sign change of charge current for charging a measuring capacitor (Cm) is evaluated using the control measurement value. The control measurement value is compared with the main measurement value. An error signal is produced when the values deviate from each other. An independent claim is also included for a device for self-monitoring of a capacitive ceramic pressure measuring cell.