Method for adjusting the volumetric flow rate ratio of at least two different fluids (F1, F2), comprising the following steps: - providing a control-device, the control-device comprising - a first chamber with a chamber-volume (V C1) for the first fluid, wherein the first chamber has an inlet-element and an outlet-element for the first fluid and at least one rotating or nutating element inside the chamber, - at least one second chamber with a chamber-volume (V C2) for the at least one second fluid, wherein the second chamber has an inlet-element and an outlet-element for the second fluid and at least one rotating or nutating element inside the chamber, - wherein the at least one rotating or nutating element of the first chamber and the at least one rotating or nutating element of the second chamber are coupled so as to rotate or nutate at a defined rotational or nutational frequency ratio, - driving the at least one rotating or nutating element of the first chamber and/or the at least one rotating or nutating element of the second chamber by the first fluid and/or the second fluid, - selecting the chamber volume ratio (V C1:V C2) and the rotational or nutational frequency ratio such that the first fluid flowing out of the outlet-element of the first chamber and the second fluid flowing out of the outlet-element of the second chamber have a predefined volumetric flow rate ratio, and characterized in that the input resistor (R i) of the respective inlet-element (3, 4) and the output resistor (R o) of the respective outlet-element (4, 8) of the first chamber and/or the second chamber are chosen so as to satisfy the equation: R iCn + R oCn η F = R T ≤ 10 14 m − 3, wherein η F is the viscosity of the respective fluid (F1, F2) and Cn designates the respective chamber. - providing a control-device, the control-device comprising - a first chamber with a chamber-volume (V C1) for the first fluid, wherein the first chamber has an inlet-element and an outlet-element for the first fluid and at least one rotating or nutating element inside the chamber, - at least one second chamber with a chamber-volume (V C2) for the at least one second fluid, wherein the second chamber has an inlet-element and an outlet-element for the second fluid and at least one rotating or nutating element inside the chamber, - wherein the at least one rotating or nutating element of the first chamber and the at least one rotating or nutating element of the second chamber are coupled so as to rotate or nutate at a defined rotational or nutational frequency ratio, - a first chamber with a chamber-volume (V C1) for the first fluid, wherein the first chamber has an inlet-element and an outlet-element for the first fluid and at least one rotating or nutating element inside the chamber, - at least one second chamber with a chamber-volume (V C2) for the at least one second fluid, wherein the second chamber has an inlet-element and an outlet-element for the second fluid and at least one rotating or nutating element inside the chamber, - wherein the at least one rotating or nutating element of the first chamber and the at least one rotating or nutating element of the second chamber are coupled so as to rotate or nutate at a defined rotational or nutational frequency ratio, - driving the at least one rotating or nutating element of the first chamber and/or the at least one rotating or nutating element of the second chamber by the first fluid and/or the second fluid, - selecting the chamber volume ratio (V C1:V C2) and the rotational or nutational frequency ratio such that the first fluid flowing out of the outlet-element of the first chamber and the second fluid flowing out of the outlet-element of the second chamber have a predefined volumetric flow rate ratio, and characterized in that the input resistor (R i) of the respective inlet-element (3, 4) and the output resistor (R o) of the respective outlet-element (4, 8) of the first chamber and/or the second chamber are chosen so as to satisfy the equation: R iCn + R oCn η F = R T ≤ 10 14 m − 3,