Compensation of a phase shift of at least one component of an electronic system of a vibronic sensor

A vibronic sensor for determining a process variable of a medium in a container, comprising:

• an electromechanical converter;
• and
• an electronic system unit including a phase adjustment unit and a compensation device, the compensation device including:
• a bridging unit for electrically bridging and thereby bypassing the electromechanical converter, wherein the bridging unit includes a bridging branch connected in parallel to the electromechanical converter;
• a signal generation unit for generating a test excitation signal in the form of an electrical alternating signal having a first selectable frequency;
• a phase detection unit for determining a first phase shift between the test excitation signal and a test receive signal that passes through the bridging unit and the component of the electronic system unit;
• and
• a computer unit configured to determine a phase compensation instruction from the first phase shift,
• wherein the compensation device is configured to transfer the phase compensation instruction to the phase adjustment unit,
• wherein the electronic system unit is configured to generate an excitation signal from a receive signal, to adjust a predeterminable phase shift between the excitation signal and the receive signal using the phase adjustment unit, and to determine the process variable from the receive signal.

A method for operating a vibronic sensor for determining and/or monitoring a process variable, comprising:

• determining in a compensation operating mode a phase compensation instruction for compensating for a phase shift caused by a component of an electronic system unit of the vibronic sensor, wherein a first test excitation signal having a first frequency and a second test excitation signal having a second frequency are used in the compensation operating mode;
• calculating a first phase shift between the first test excitation signal and a first test receive signal and a second phase shift between the second test excitation signal and a second test receive signal;
• calculating from the values of the first frequency, the second frequency, the first phase shift, and the second phase shift a polynomial function of predeterminable order as the phase compensation instruction;
• adjusting in a measurement operating mode a predeterminable phase shift between an excitation signal and a receive signal;
• adjusting the predeterminable phase shift using the phase compensation instruction;
• and
• determining the process variable.