Coriolis mass flowmeter determining state of wear of the pipe

The invention concerns a Coriolis mass flowmeter comprising at least one conduit ( 9 ) traversed by the mass, which produces mechanical vibrations under the effect of an excitation unit ( 8 ) and acts as an oscillating element, whereof the oscillating behaviour which varies based on the mass flow rate is sensed by at least one sensor ( 15, 16 ) to determine the mass flow. The invention aims at determining the degree of wear of the conduit ( 9 ). Therefor, the excitation unit ( 8 ) applies a single excitation pulse to the conduit ( 9 ), whereof the oscillatory response is sensed by the sensor ( 15; 16 ). The invention is characterized in that an evaluating unit ( 10 ) arranged downstream calculates the initial dampening constant recorded when the conduit ( 9 ) was new.