Process for operating a measurement device of the vibration type

A process is disclosed for operating a measurement device of the vibration type in which at least one exciter arrangement excites the system to vibration and from the vibration parameters, a measurement quantity of a measurement medium in a tube system is determined. A time-dependent force f(t)=F sin(ωt)+g(t) with at least one sinusoidal component with an adjustable frequency ω can be used which acts on at least one vibration-capable part of the measurement device of the vibration type. A response signal of the vibration-capable part, (e.g., its time dependent velocity v(t)=V sin(ωt+ψ)+h(t)) can be measured, and a phase shift Ψ between the response signal and the force f of a signal component which oscillates with a frequency ω is determined. The phase shift Ψ can be used as the input for a frequency controller so that the excitation frequency is automatically adjusted as a function of Ψ.