Abstract: A Coriolis mass meter with two tube sections connected by a coupling extending between connection points of the tube sections wherein the coupling extends a distance between the connection points which exceeds the shortest perpendicular distance between the first and the second tube sections. The coupling facilitates less stiffness of the tubes against Coriolis oscillation and thus provides a mass meter with a stronger and potentially more reliable measuring signal.

Abstract: The invention concerns an ultrasonic transducer, which is assembled from several parts. These parts are a protecting plate, a piezoelectric disc and a housing. Joining of the parts for transducers are normally done by means of TIG welding or laser welding, but these are relatively costly processes, which also has an impact on the transducer, especially the piezoelectric disc, due to the heat. In order to reduce the heat load and simultaneously simplify manufacturing an ultrasonic transducer is suggested, in which the protecting plate and the housing consists of electrically conducting materials of different kinds and where joining of housing and plate is done by using a mechanical force influence and an electrical current which flows through plate and housing. Also, a method for joining the parts of an ultrasonic transducer is described.

Abstract: In a method for measuring flow by means of an ultra sonic flow meter, an ultra sonic signal is transmitted in an upstream and a downstream direction. This is measured upon receipt of an ultra sonic signal and the measurement stopped at a stopping point. A first series of transmissions is made, and the starting time of each transmission is incremented or decremented until a time difference between the upstream and downstream signal is inside a reference band. Flow is then calculated in accordance with the time measurements.

Abstract: A device having a first flow meter (2) and a second flow meter (3). The first and the second flow meters work according to a Coriolis principle. The first flow meter includes a first measuring tube (7). The second flow meter includes a second measuring tube (10). The first flow meter and the second flow meter are disposed in a common housing (4,5,6). The first flow meter and the second flow meters have different eigenfrequencies because of a first vibration-influencing device (18) attached to the first flow meter and a second vibration-influencing device (19) attached to the second flow meter.

Abstract: A transmitting and receiving circuit for an ultrasonic flowmeter. In such circuits, an ultrasonic transducer is typically used as both transmitter and receiver. This is obtained by using switching means, for example in the form of CMOS switches. However, problems arise with ringings of a transducer when having acted as a transmitter. This unwanted ringing makes the crystal of the transducer act as an additional signal generator, and the signal is coupled via parasitic capacitances in a switching means to the receiving ultrasonic transducer. This problem is solved by connecting one pole of a short circuit switch (S3, S4) to the ultrasonic transducer (TR1, TR2) or to the switching means (S1, S2) and the other pole of the short circuit switch to ground. Keeping the short circuit switch closed when the switching means is open, and open when the switching means is closed, creates a decoupling path for the unwanted signal, thereby improving the accuracy of the transmitting and receiving circuit.

Abstract: An insert for a measuring tube of an inductive flowmeter is disclosed, having a middle section and two end sections, in which at least one end section is of resilient construction and the middle section is of rigid construction. A flange constituting an earthing electrode is provided in a section B2B comprising electrically conductive elastomer. Integrally-formed electrodes 12 and 13 are also formed by electrically conductive elastomer.

Abstract: A method for testing an electromagnetic flowmeter and a flowmeter are described, the flowmeter having a measuring tube (2) and a coil arrangement (3, 4) for generating a magnetic field perpendicular to the direction of flow through the measuring tube (2), the current direction in the coil arrangement being periodically changed. In this connection, it is desirable for simple monitoring to be possible. For that purpose, after changing the current direction, at least one parameter of the current rise is determined and this is compared with a reference value. For this, the flowmeter has a testing device (20, 25) which, after a change-over of the current direction, determines at least one parameter (T) of the rise in the current in the coil arrangement (3, 4, 30) and compares it with a given value.

Abstract: A mass flow measuring apparatus (1) is described, having tube (2), which at a first position (P1) is coupled as regards oscillation to a first energy converter (4) and at a second position (P2) is coupled as regards oscillation to a second energy converter (5), and having an evaluating device, the first and the second position (P1, P2) being spaced (L) from one another, the energy converters (4, 5) each being operable as oscillation generator and oscillation detector and the energy converters (4, 5) working alternately as oscillation generators. A method can therefore be carried out in which the tube (2) is caused to oscillate alternately at the first position (P1) and at the second position (P2), signals being measured at the second and the first position (P2, P1). It is desirable to be able to achieve accurate measurements even in the case of a measuring apparatus of small construction.