US 12,674,693 B2Granted

Method for operating a magnetic-inductive flowmeter and a corresponding magnetic-inductive flowmeter

AssigneeKROHNE Messtechnik GmbH

InventorJan Förster

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Abstract

A method for operating a magnetic-inductive flowmeter includes: generating polarized measurement data dependent on a polarity of a magnetic field passing through a measuring tube; obtaining a frequency spectrum independent of the magnetic field by a discrete frequency analysis of the polarized measurement data; obtaining a magnetic field-dependent frequency spectrum by a discrete frequency analysis of depolarized measurement data derived from the polarized measurement data; examining amplitude values of the magnetic field-independent frequency spectrum for a magnetic field-independent event, and/or examining amplitude values of the magnetic field-dependent frequency spectrum for a magnetic field-dependent event; and identifying and signaling the presence of a magnetic field-independent event and/or a magnetic field-dependent event. A related magnetic-inductive flowmeter is also disclosed.

Claims14

Dependent claims

A method for operating a magnetic-inductive flowmeter with a measuring tube for guiding a medium, with a magnetic field generator for generating a magnetic field of alternating magnetic field polarity passing through the measuring tube perpendicular to the direction of flow of the medium, with a pair of electrodes for tapping an electrical voltage induced in the medium as a measuring signal, wherein measurement data obtained from the measuring signal is transformed from a time domain into a frequency domain and the measuring signal is processed at least into a flow measurement value, the method comprising:

generating from the measuring signal at least one measurement data set with polarized measurement data dependent on the magnetic field polarity from time domains of different magnetic field polarity;
obtaining at least one frequency spectrum independent of the magnetic field by a discrete frequency analysis of the measurement data set with polarized measurement data;
deriving at least one measurement data set with depolarized measurement data from the measurement data set with polarized measurement data;
obtaining at least one magnetic field-dependent frequency spectrum by a discrete frequency analysis of the measurement data set with depolarized measurement data;
in an evaluation step, at least one of:
(i) examining amplitude values of the magnetic field-independent frequency spectrum for at least one magnetic field-independent event by peak detection;
and (ii) examining amplitude values of the magnetic field-dependent frequency spectrum for at least one magnetic field-dependent event;
and
signaling the presence of an event when at least one of the magnetic field-independent event and the magnetic field-dependent event is identified.

6 more elements

A magnetic-inductive flowmeter, comprising:

a measuring tube for guiding a medium;
a magnetic field generator for generating a magnetic field of alternating magnetic field polarity passing through the measuring tube perpendicular to the direction of flow of the medium;
a pair of electrodes for tapping an electrical voltage induced in the medium as a measuring signal;
wherein a signal processing device obtains measurement data from the measuring signal, the signal processing device transforms the measurement data from a time domain into a frequency domain;
wherein the signal processing device processes the measuring signal into a flow measurement value;
wherein the signal processing device in an operating state of the magnetic-inductive flowmeter generates from the measuring signal at least one set of measurement data with polarized measurement data dependent on the magnetic field polarity from time domains of different magnetic field polarity;
wherein the signal processing device obtains at least one frequency spectrum independent of the magnetic field by a discrete frequency analysis of the measurement data set with polarized measurement data;
wherein the signal processing device derives at least one measurement data set with depolarized measurement data from the measurement data set with polarized measurement data;
wherein the signal processing device obtains at least one magnetic field-dependent frequency spectrum by a discrete frequency analysis of the measurement data set with depolarized measurement data;
wherein, in an evaluation step, the signal processing device at least one of:
(i) examines amplitude values of the magnetic field-independent frequency spectrum for at least one magnetic field-independent event by peak detection;
and (ii) examines amplitude values of the magnetic field-dependent frequency spectrum for at least one magnetic field-dependent event;
and
wherein upon identification of at least one of a magnetic field-independent event and a magnetic field-dependent event, the signal processing device signals the presence of the event.

11 more elements

Dependencies are inferred from the claim text.