Measurement system for measuring a flow parameter of a fluid measurement substance flowing in a pipeline

A measurement system for measuring at least one time-variable flow parameter of a measurement substance flowing in a pipeline, the measurement system comprising:

• a pipe defining a lumen, configured to be insertable into a course of the pipeline, and configured to guide the measurement substance flowing in the pipeline or to enable the measurement substance to flow therethrough;
• a prismatic or cylindrical bluff body arranged in the lumen of the pipe and configured to generate vortices in the measurement substance flowing passed at a shedding frequency dependent on a current flow velocity of the measurement substance such that a Kármán vortex street is formed in the fluid flowing downstream of the bluff body;
• a vortex sensor arranged downstream of the bluff body,
• which has at least one mechanical resonant frequency, which is a lowest, and/or always above, the shedding frequency, and
• which is configured, in a manner excited by the flowing measurement substance, to effect mechanical oscillations around a static rest position and to provide at least one electrical or optical, vortex sensor signal, which at least one vortex sensor signal:
• represents the oscillations;
• includes a first spectral component representing oscillations of the vortex sensor with the shedding frequency, the first spectral component having a signal level not below a predetermined first threshold value for signal noise;
• and
• includes a second spectral component representing resonance oscillations of the vortex sensor with the mechanical resonance frequency thereof, the second spectral component having a signal level not below a predetermined second threshold value for signal noise;
• and
• converter electronics including at least one microprocessor and configured to evaluate the at least one vortex sensor signal and to determine measurement values for the at least one flow parameter,
• wherein the converter electronics are configured to receive and evaluate the at least one vortex sensor signal, including to determine at least:
• vortex frequency measurement values representing the shedding frequency based on the first spectral component of the at least one vortex sensor signal;
• and
• amplitude measurement values that represent an amplitude of the resonance oscillations of the vortex sensor based on the second spectral component, and
• wherein the converter electronics are further configured:
• using one or more amplitude measurement values, to determine:
• whether and/or to what extent the measurement substance contains a foreign substance;
• and/or
• whether the measurement substance is embodied as a single-phase or multi-phase substance;
• and
• using one or more vortex frequency measurement values, to calculate flow parameter measurement values, which are measurement values for the at least one flow parameter, such that the flow parameter measurement values each comply with a calculation rule, as follows:
• X
• M
• =
• k
• M
• ·
• X
• f