Method for verifying a useful signal component of a periodic sensor signal

A method for verifying a periodic useful signal component of a sensor signal of a flowmeter, wherein the flowmeter comprises one of a vortex flowmeter, an electromagnetic flowmeter, or a Coriolis mass flowmeter, and wherein the useful signal component of the sensor signal is used to determine a flow measured value of a flowing medium, comprising engaging the flowmeter to generate the sensor signal and a method cycle of:

• a detection step of detecting a periodic measured variable over a period t1, and outputting a periodic sensor signal based on the detected periodic measured variable,
• an analysis step of subjecting the sensor signal to a time/frequency analysis, and determining a time-dependent frequency spectrum of the sensor signal, wherein the time-dependent frequency spectrum of the sensor signal contains information about both a frequency and an amplitude of the sensor signal over time,
• an examination step of examining the time-dependent frequency spectrum for an expected characteristic feature which is characteristic of a useful signal, and one of:
• a verification step of verifying a portion of the sensor signal having the characteristic feature as the useful signal component if the characteristic feature is found in the time-dependent frequency spectrum and determining a measured flow value of the flowmeter based on the verified useful signal component, or
• a rejection step of rejecting a portion of the sensor signal which does not have the characteristic feature as an interference signal component if the characteristic feature is not found in the time-dependent frequency spectrum,
• the method further comprising selecting a subsection of the time-dependent frequency spectrum in a subsection selection step to identify the characteristic feature, and subjecting the subsection to a further time/frequency analysis in a subsection analysis step.