A vibronic measuring system for measuring and/or monitoring at least one flow parameter and/or for measuring and/or monitoring at least one substance parameter of a flowing measured substance, the vibronic measuring system comprising:
- a transducer including a tube assembly for conducting the flowing measured substance, an exciter assembly for converting electrical power into mechanical power used to excite and maintain forced mechanical vibrations of the tube assembly, and a sensor assembly for detecting mechanical vibrations of the tube assembly and for providing vibration signals respectively representing vibration movements of the tube assembly;
- and
- a measuring system electronics unit that is electrically coupled to the transducer, including both to the exciter assembly and to the sensor assembly, that is formed by at least one microprocessor, that is arranged in an electronics protective housing, and that is embodied for controlling the transducer and for evaluating vibration signals provided by the transducer,
- wherein the tube assembly includes a first tube, and at least a second tube,
- wherein each of the first and second tubes of the tube assembly extends in each case from a respective first end of the respective tube to a respective second end of the same tube with a respective tube length and has in each case a lumen enclosed by a tube wall extending from the respective first end of the respective tube to the respective second end of the same tube,
- wherein each of the first and second tubes of the tube assembly is configured to be traversed by the flowing measured substance and to be vibrated,
- wherein the exciter assembly includes two vibration exciters of which a first vibration exciter is mechanically connected to the first tube and positioned centrally on the first tube, and a second vibration exciter is mechanically connected to the second tube and positioned centrally on the second tube,
- wherein each of the first and second vibration exciters is configured in each case to convert electrical power with a time-varying electrical current into mechanical power in such a way that a time-varying driving force acts on the first or second tube at a respective point of application formed by the respective vibration exciter on the tube mechanically connected thereto in each case,
- wherein the sensor assembly includes at least four vibration sensors of which a first vibration sensor and a second vibration sensor are positioned on the first tube spaced apart from one another and a third vibration sensor and a fourth vibration sensor are positioned on the second tube spaced apart from one another,
- wherein each of the first and second vibration sensors is in each case configured to detect vibration movements of the first tube and to convert the vibration movements of the first tube into a first or second vibration signal representing the vibration movements of the first tube such that each of the first and second vibration signals in each case contains one or more sinusoidal signal components having a frequency corresponding to a vibration frequency of vibration movements of the first tube,
- wherein each of the third and fourth vibration sensors is in each case configured to detect vibration movements of the second tube and to convert the vibration movements of the second tube into a respective third or fourth vibration signal representing the vibration movements of the second tube such that each of the third and fourth vibration signals in each case contains one or more sinusoidal signal components having a frequency corresponding to a vibration frequency of vibration movements of the second tube,
- wherein the measuring system electronics unit is configured to feed an electrical first drive signal into the first vibration exciter by which the first tube performs forced mechanical bending vibrations at one or more vibration frequencies predefined by the first drive signal and simultaneously to feed an electrical second drive signal into the second vibration exciter by which the second tube performs forced mechanical bending vibrations at one or more vibration frequencies predefined by the second drive signal,
- wherein the measuring system electronics unit is further configured, in a first operating mode, to generate the first drive signal with a first useful current component having a sinusoidal current component that is dominant with respect to a current intensity or the only sinusoidal current component, with an alternating frequency and a phase angle, and feed the first drive signal into the first vibration exciter, and to generate the second drive signal with a first useful current component having a sinusoidal current component that is dominant with respect to a current intensity or the only sinusoidal current component, with an alternating frequency corresponding to the alternating frequency of the first useful current component of the first drive signal and a phase angle deviating from the phase angle of the first useful current component of the first drive signal and to feed the second drive signal into the second vibration exciter, in such a way:
- that the first and second drive signals have a first drive phase difference between the phase angles of their respective first useful current components,
- that the first tube at least partially performs first useful mechanical vibrations forced by the first vibration exciter having a first useful vibration frequency corresponding to the alternating frequency of the first useful current component of the first drive signal and with a first useful vibration phase corresponding to the phase angle of the first useful current component of the first drive signal, and the second tube performs at least partially second useful mechanical vibrations forced by the second vibration exciter having the first useful frequency and with a second useful vibration phase corresponding, at least at the location of the second vibration exciter, to the phase angle of the first useful current components of the second drive signal, and
- that each of the first, second, third and fourth vibration signals in each case has a respective first useful signal component that is a respective sinusoidal signal component having a frequency corresponding to the first useful frequency,
- wherein the measuring system electronics unit is further configured, in a second operating mode, to generate the first drive signal with a second useful current component having a dominant or single sinusoidal current component with respect to a current intensity or the only sinusoidal current component with an alternating frequency and a phase angle and to feed the first drive signal into the first vibration exciter, and to generate the second drive signal with a second useful current component that is a sinusoidal current component that is dominant with respect to a current intensity or the only sinusoidal current component with an alternating frequency corresponding to the alternating frequency of the second useful current component of the first drive signal and a phase angle that deviates from the phase angle of the second useful current component of the first drive signal by less than 180°, and corresponding to the phase angle of the second useful current component of the first drive signal and to feed the second drive signal into the second vibration exciter in such a way:
- that the first and second drive signals have a second drive phase difference, namely a difference between the phase angles of their second useful current components, that deviates from the first drive phase difference,
- that the first tube performs third useful mechanical vibrations forced by the first vibration exciter with at least a second useful vibration frequency corresponding to the alternating frequency of the second useful current component of the first drive signal, and with a third useful vibration phase corresponding, at least at the location of the first vibration exciter, to the phase angle of the second useful current component of the first drive signal, and the second tube performs at least partially fourth useful mechanical vibrations forced by the second vibration exciter with the second useful frequency and with a fourth useful vibration phase correspondingly, at least at the location of the second vibration exciter, to the phase angle of the second useful current components of the second drive signal such that the fourth useful vibrations are in phase with the third useful vibrations, and
- that each of the first, second, third and fourth vibration signals in each case has a second useful sinusoidal signal component having a frequency corresponding to the second useful frequency, and
- wherein the measuring system electronics unit is further configured:
- in the first operating mode, to receive and evaluate the first, second, third, and fourth vibration signals, including to determine measured values quantifying the at least one physical measured variable based on the vibration signals, and
- and, in the second operating mode, to receive and evaluate the first, second, third, and fourth vibration signals, and, based on the first and third and/or second and fourth vibration signals received in the second operating mode, to calibrate the measuring system and/or to check the measuring system or to detect whether a fault of the measuring system is present.