CORIOLIS MASS FLOWMETER

The Coriolis mass flowmeter comprises a measuring transducer having at least one measuring tube (10), an exciter mechanism and a sensor arrangement as well as, both electrically coupled with the exciter mechanism as well as also with the sensor arrangement, an electronic transmitter circuit (ME) having a measurement- and control electronics (MCE) and a drive electronics (Exc) connected to the measuring and control electronics and/or driven by the measuring and control electronics. The measuring tube is adapted to convey a fluid measured substance flowing at least at times and during that to be caused to vibrate. Additionally, the exciter mechanism is adapted to convert electrical power supplied to it into forced mechanical power effecting mechanical oscillations of the at least one measuring tube and the sensor arrangement is adapted to register mechanical oscillations of the at least one measuring tube and to provide a first oscillation measuring signal (s1) representing, at least in part, oscillatory movements of the at least one measuring tube as well as to provide at least a second oscillation measuring signal (s2) representing, at least in part, oscillatory movements of the at least one measuring tube, in such a manner that the oscillation measuring signals follow a change of a mass flow rate of the measured substance guided in the measuring tube with a change of a phase difference, namely a change of a difference between a phase angle of the first oscillation measuring signal (s1) and a phase angle of the second oscillation measuring signal (s2). The sensor arrangement is, additionally, electrically coupled with the measuring and control electronics. The drive electronics is, in turn, electrically connected with the exciter mechanism and is adapted, in a first operating mode (I), to generate an electrical driver signal (e1) and therewith to supply electrical power to the exciter mechanism, in such a manner that the at least one measuring tube executes forced mechanical oscillations having at least one wanted frequency, namely an oscillation frequency predetermined by the electrical driver signal, and, in a second operating mode (II), to cease generating the electrical driver signal, in such a manner that then no electrical power is supplied by the drive electronics to the exciter mechanism. In the case of the Coriolis mass flowmeter of the invention, the transmitter circuit is, additionally, adapted to switch the drive electronics from the operating