US 12,405,143 B2
Method for operating a magnetic-inductive flowmeter and a corresponding magnetic-inductive flowmeter
Jan Förster, Essen (DE); and Nicolaus Mathies, Moers (DE)
Filed by KROHNE Messtechnik GmbH, Duisburg (DE)
Filed on Jun. 23, 2023, as Appl. No. 18/340,317.
Claims priority of application No. 102022115787.3 (DE), filed on Jun. 24, 2022.
Prior Publication US 2023/0417585 A1, Dec. 28, 2023
Int. Cl. G01F 1/58 (2006.01)
CPC G01F 1/588 (2013.01) [G01F 1/586 (2013.01)] 12 Claims
OG exemplary drawing
 
1. 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 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 in the measuring tube as a measuring signal induced in the medium in the measuring tube, and having a control and evaluation device for determining a flow measurement value from the measuring signal, wherein the measuring signal is sampled a plurality of times in a measuring window periodically repeating at a measuring window frequency, and at least one averaged flow measurement value is determined from the multiple sampled measurement signals from at least one measuring window, the method comprising:
obtaining an amplitude spectrum of the sampled measuring signals of at least one measuring window by a frequency analysis of the multiple, sampled measuring signals;
determining at least one interference peak in the amplitude spectrum and the associated interference peak frequency by a peak detection, wherein the at least one interference peak has a peak frequency that is not a multiple of the measuring window frequency;
identifying a critical measurement situation is identified by checking whether the determined interference peak frequency falls below a predetermined critical frequency distance to a multiple of the measuring window frequency; and
in the presence of a critical measurement situation, determining a new measuring window frequency and setting the new measuring window frequency as the measuring window frequency, so that a critical measurement situation is no longer present.