US 12,169,136 B2
Method for operating a magneto-inductive flowmeter, and magneto-inductive flowmeter
Andre Spahlinger, Bad Bellingen (DE); André Schaubhut, Schopfheim (DE); Heinz Rufer, Dornach (CH); and Thomas Küng, Münchenstein (CH)
Assigned to Endress+Hauser Flowtec AG, Reinach (CH)
Appl. No. 17/756,960
Filed by Endress+Hauser Flowtec AG, Reinach (CH)
PCT Filed Nov. 20, 2020, PCT No. PCT/EP2020/082905
§ 371(c)(1), (2) Date Jun. 6, 2022,
PCT Pub. No. WO2021/110442, PCT Pub. Date Jun. 10, 2021.
Claims priority of application No. 102019133462.4 (DE), filed on Dec. 6, 2019.
Prior Publication US 2023/0015365 A1, Jan. 19, 2023
Int. Cl. G01F 1/58 (2006.01)
CPC G01F 1/588 (2013.01) [G01F 1/58 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for operating a magneto-inductive flowmeter,
wherein the magneto-inductive flowmeter has a measuring tube for conducting a flowable medium, at least two measurement electrodes for detecting a flow-velocity-dependent measurement voltage induced in the medium and a magnetic-field generating device for generating a magnetic field passing through the measuring tube,
wherein the magnetic-field-generating device has a coil;
comprising the method steps:
applying a control voltage to the coil in order to generate a change in the coil current over time; and
determining the change in the coil current over time in a change-over region,
wherein, in the change-over region, a change in the coil current is present until a target coil current I_target is reached;
wherein the change-over region comprises a γ time range (γ),
wherein the change in the coil current over time in the γ time range (γ) is determined,
wherein the γ time range (γ) is immediately followed by a δ time range (δ), in which the change in the coil current has an opposite sign to the change in the coil current in the γ time range (γ);
wherein the γ time range (γ) has a γ time range start (T_(γ start)),
wherein, in the γ time range start (T_(γ start)), a value of the coil current is at least 75% of a value of the target coil current I_target.