Method for balancing a first oscillating element and a second oscillating element second oscillating element of an oscillating fork, which is part of a sensor unit of a device for determining and/or monitoring at least one process variable of a medium, wherein the sensor unit comprises at least two piezoelectric elements (11a, 11b), wherein a first piezoelectric element is at least partially arranged in the first piezoelectric element, wherein a second piezoelectric element is arranged at least partially in the second oscillating element, wherein an electronic system of the device has at least a first adjustable impedance element, which is connected in series with the first piezoelectric element, the electronic system having a second impedance element which is connected in series with the second piezoelectric element, and wherein the method comprises the following method steps: Excitation of the first oscillating element to mechanical oscillations by means of a balancing excitation signal, Receive a first balancing receive signal, Excitation of the second oscillating element to mechanical oscillations by means of the balancing excitation signal, Receive a second balancing receive signal, Comparing the first and second balancing receive signals and adjusting the first impedance element and the second impedance element based on the comparison, whereby one oscillating element (9a, 9b) is mechanically blocked, while the other oscillating element (9a, 9b) is excited to oscillate. second oscillating element of an oscillating fork, which is part of a sensor unit of a device for determining and/or monitoring at least one process variable of a medium, wherein the sensor unit comprises at least two piezoelectric elements (11a, 11b), wherein a first piezoelectric element is at least partially arranged in the first piezoelectric element, wherein a second piezoelectric element is arranged at least partially in the second oscillating element, wherein an electronic system of the device has at least a first adjustable impedance element, which is connected in series with the first piezoelectric element, the electronic system having a second impedance element which is connected in series with the second piezoelectric element, and wherein the method comprises the following method steps: Excitation of the first oscillating element to mechanical oscillations by means of a balancing excitation signal, Receive a first balancing receive signal, Excitation of the second oscillating element to mechanical oscillations by means of the balancing excitation signal, Receive a second balancing receive signal, Comparing the first and second balancing receive signals and adjusting the first impedance element and the second impedance element based on the comparison, whereby one oscillating element (9a, 9b) is mechanically blocked, while the other oscillating element (9a, 9b) is excited to oscillate. Excitation of the first oscillating element to mechanical oscillations by means of a balancing excitation signal, Receive a first balancing receive signal, Excitation of the second oscillating element to mechanical oscillations by means of the balancing excitation signal, Receive a second balancing receive signal, Comparing the first and second balancing receive signals and adjusting the first impedance element and the second impedance element based on the comparison, whereby one oscillating element (9a, 9b) is mechanically blocked, while the other oscillating element (9a, 9b) is excited to oscillate.