US 12,306,027 B2
Method for operating a measuring device with at least one oscillator, and measuring device for carrying out said method
Rémy Scherrer, Oberdorf (FR); Robert Lalla, Lörrach (DE); Reinhard Huber, Bad Säckingen (DE); and Martin Josef Anklin, Dornach (CH)
Assigned to ENDRESS+HAUSER FLOWTEC AG, Reinach (CH)
Appl. No. 17/642,481
Filed by Endress+Hauser Flowtec AG, Reinach (CH)
PCT Filed Aug. 20, 2020, PCT No. PCT/EP2020/073395
§ 371(c)(1), (2) Date Mar. 11, 2022,
PCT Pub. No. WO2021/047887, PCT Pub. Date Mar. 18, 2021.
Claims priority of application No. 10 2019 124 709.8 (DE), filed on Sep. 13, 2019.
Prior Publication US 2022/0307884 A1, Sep. 29, 2022
Int. Cl. G01F 1/84 (2006.01); G01F 15/02 (2006.01)
CPC G01F 1/8436 (2013.01) [G01F 1/8472 (2013.01); G01F 15/022 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for operating a measuring device having a measuring sensor having an oscillator, wherein the oscillator includes a vibratory measuring tube for conducting a medium, the method comprising:
determining a current value of a resonance frequency for a vibration mode of the oscillator;
exciting a resonance vibration of the oscillator with an excitation current signal;
exciting a vibration of the oscillator that is out of resonance, with another excitation current signal and with an excitation frequency that differs from the current value of the resonance frequency, and wherein the vibration out of resonance is superimposed on a vibration at the resonance frequency; wherein the resonance vibration and the vibration out of resonance are excited simultaneously;
detecting via a low-pass filter a sensor signal of a vibration sensor of the oscillator, wherein a time constant of the low pass filter is not less than 1,000 period lengths of the vibration out of resonance;
determining an amplitude of the sensor signal which represents the vibration out of resonance; and
determining a change to a stiffness or a flexibility of the oscillator has occurred, based on the determined amplitude of the sensor signal.