Abstract: According to the invention, a digital processor (DSP) is provided in a measuring and operating circuit for a Coriolis-type mass flowmeter. From the vibration sensor signals, said digital processor evaluates only the differential signal (S) and the one sensor signal (S1). The in-phase component (I) and the quadrature components (Q) are determined for the differential signal (D), and the amplification of the second sensor signal (S2) is controlled in such a manner that the in-phase component (I) vanishes. The mass flow rate (m) is determined from the quadrature component (Q).

Abstract: Such an excitation circuit is intended for use in a Coriolis mass flowmeter which is connected to, is powered exclusively from, and outputs a measurement signal exclusively via, a two-wire process control loop. The Coriolis mass flowmeter has a vibrating flow tube and an excitation assembly for vibrating the flow tube at a frequency equal or adjacent to the instantaneous mechanical resonance frequency of the flow tube. It further comprises transducer assemblies which are positioned at a given distance from each other along the flow tube and provide respective transducer signals.

Abstract: A vibration meter and a method of measuring a viscosity of a fluid flowing through a pipe are disclosed. The vibration meter comprises meter electronics and a transducer assembly with an electromechanical excitation arrangement and with a flow tube which oscillates in operation. A sensor arrangement produces sensor signals representative of inlet-side and outlet-side deflections of the flow tube. An evaluation circuit derives from said sensor signals and from an excitation current generated by an excitation circuit for the excitation arrangement a viscosity value representative of the viscosity of the fluid.

Abstract: A Coriolis mass flow/density sensor is provided. The sensor includes a measuring tube for conducting a fluid. The measuring tube is fixed in a support and may be coupled to a pipe via an inlet tube and an outlet tube. The sensor further includes an excitation arrangement for vibrating the measuring tube in a predetermined vibration mode, a sensor arrangement for detecting vibrations of the measuring tube, and a brake assembly coupled to the measuring tube and the support. The brake assembly is operable to suppress at least one mode of vibrations other than the predetermined vibration mode.

Abstract: The present Coriolis mass/flow density meter and method for measuring a mass flow rate of a medium flowing through a flow tube of a Coriolis mass flow meter provide measurement results which are independent of the current velocity field of the medium to be measured. At least one measuring tube is provided, through which the medium flows, which oscillates during operation. A means for measuring the oscillations is arranged at an inlet end of the measuring tube and provides a measurement signal. A second means for measuring the oscillations is arranged at the outlet of the measuring tube and provides a second measurement signal. A third measuring means provides a third measurement signal which represents the current Reynolds number of the flowing medium, Evaluation electronics generate a measurement value representing the mass through-flow. The evaluation electronics also generate a measurement value representing the current density of the medium.

Abstract: Such an excitation circuit is intended for use in a Coriolis mass flowmeter which is connected to, is powered exclusively from, and outputs a measurement signal exclusively via, a two-wire process control loop. The Coriolis mass flowmeter has a vibrating flow tube and an excitation assembly for vibrating the flow tube at a frequency equal or adjacent to the instantaneous mechanical resonance frequency of the flow tube. It further comprises transducer assemblies which are positioned at a given distance from each other along the flow tube and provide respective transducer signals.

Abstract: This mass flow/density sensor (10), which can be installed in a pipe and through which a fluid to be measured flows during operation, is to be balanced over a wide density range, so that accurate measurements are possible. A single straight measuring tube (13) having a longitudinal axis (131) extends between its inlet end (11) and the outlet end (12) and is fixed to a support, e.g., a cylindrical tube (14, 14′). The support has a longitudinal centroidal line (141) which is parallel to, but does not coincide with, the longitudinal axis (131) of the measuring tube. A cantilever (15) is fixed to the measuring tube (13) midway between the inlet and outlet ends (11, 12) and in operation causes the measuring tube to vibrate either in a first fundamental flexural mode or in a second fundamental flexural mode having a higher frequency than this first mode. An excitation arrangement (16) disposed midway between the end pieces excites the measuring tube (13) in the second mode.

Abstract: This circuit is suitable for flow tubes (4) the vibration frequency of which is in the order of 1 kHz. A fluid to be measured flows through the tube (4) vibrating in operation at a frequency determined by the density of the fluid. Attached to the tube (4) are electromagnetic vibration sensors (17, 18) positioned at a given distance from each other delivering sinusoidal sensor signals (x17, x18). Impedance-matching devices (31, 32) are fed by the sensor signals. Inputs of an intermediate switch (35) are connected to the outputs of impedance-matching devices. Additional impedance-matching device (33, 34) are fed by outputs of the intermediate switch. Low-pass filters (37, 38) are connected to the outputs of the additional impedance matching devices. The upper cutoff frequency of low-pass filter (37) differs by about 10% to 15% from the upper cutoff frequency of low-pass filter (38). Zero-crossing detector (39, 40) are fed by the outputs of the low-pass filters.

Abstract: A Coriolis mass flow/density sensor which can be installed in a pipe and through which a fluid to be measured flows during operation is balanced over a wide density range so that accurate measurements are possible. The Coriolis mass flow/density sensor includes a measuring tube, an excitation arrangement for exciting the measuring tube to vibrate in a second fundamental flexural mode of vibration; and a counterbalance member attached to the measuring tube which counterbalances the vibration of the measuring tube. A cantilever can be attached to the measuring tube midway between the inlet end and the outlet end of the measuring tube. First and second sensors sense the measuring tube vibration on the inlet and outlet sides of the measuring tube, respectively.

Abstract: A vibration meter and a method of measuring a viscosity of a fluid flowing through a pipe are disclosed. The vibration meter comprises meter electronics and a transducer assembly with an electromechanical excitation arrangement and with a flow tube which oscillates in operation. A sensor arrangement produces sensor signals representative of inlet-side and outlet-side deflections of the flow tube. An evaluation circuit derives from said sensor signals and from an excitation current generated by an excitation circuit for the excitation arrangement a viscosity value representative of the viscosity of the fluid.

Abstract: This mass flow/density sensor (10), which can be installed in a pipe and through which a fluid to be measured flows during operation, is to be balanced over a wide density range, so that accurate measurements are possible. A single straight measuring tube (13) having a longitudinal axis (131) extends between its inlet end (11) and the outlet end (12) and is fixed to a support, e.g., a cylindrical tube (14, 14'). The support has a longitudinal centroidal line (141) which is parallel to, but does not coincide with, the longitudinal axis (131) of the measuring tube. A cantilever (15) is fixed to the measuring tube (13) midway between the inlet and outlet ends (11, 12) and in operation causes the measuring tube to vibrate either in a first fundamental flexural mode or in a second fundamental flexural mode having a higher frequency than this first mode. An excitation arrangement (16) disposed midway between the end pieces excites the measuring tube (13) in the second mode.

Abstract: This Coriolis mass flow sensor (40, 50, 60, 70) can be inserted in a pipeline by means of an inlet-side and an outlet-side connecting element (402, 403; 502, 503; 602, 603; 702, 703). An oscillating system comprises at least one measuring tube (401; 501; 601; 701, 701'), through which a fluid to be measured flows in operation. The oscillations of the oscillating system are excited by means of an electromagnetic exciter arrangement (1, 2, 3, 4, 10) which has at least one low-resistance exciter coil (15; 251, 252; 35) fed from an exciter current source (6, 7), a core (13, 23, 33, 43, 53) containing a permanent magnet (12; 221, 222; 32; 42; 512, 522), and an armature (14, 24, 34, 44, 54, 104). The oscillating system can also be excited by interference vibrations which contain a frequency which is the same as the resonant frequency of the oscillating system, such that the measurement result is corrupted.