Patent ID: 11920972
Assignee: ENDRESS+HAUSER SE+CO. KG
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 5:
6. A method for state monitoring of a coil that is a part of a device for determining at least one process variable of a medium in a containment, the method comprising:
supplying the coil with an alternating electrical excitation signal and varying a frequency of the excitation signal from a starting frequency to an ending frequency;
receiving an electrical received signal from the coil during the varying of the frequency of the excitation signal;
measuring a phase shift between the excitation signal and the received signal;
ascertaining a first frequency for the excitation signal such that a phase shift between the excitation signal and the received signal at the first frequency is less than a predeterminable limit value;
comparing an actual value for the first frequency with a desired value for the first frequency;
ascertaining a state indicator for the coil based on a deviation of the actual value of the first frequency from the desired value of the first frequency;
generating a report regarding a maintenance to be performed when the deviation of the actual value of the first frequency from the desired value of the first frequency is less than a predeterminable value; and
outputting a report regarding a defect of the coil when the deviation of the actual value from the desired value is greater than the predeterminable value.