Abstract:
A method for detecting accretion or abrasion on a first measuring tube of a flow measuring device. A first temperature as a function of time is registered via a first temperature sensor, which is arranged on the first measuring tube in such a manner that, between the first temperature sensor and the medium, at least one measuring tube wall of the first measuring tube is embodied. Parallel in time, a second reference temperature as a function of time is registered by a second temperature sensor, which is spaced from the first temperature sensor and thermally coupled to the medium. Therefrom, at least one variable characteristic is determined, and accretion or abrasion on the first measuring tube is detected, if the at least one determined characteristic variable or a variable derived therefrom deviates by more than a limit value from a predetermined reference variable.
Abstract:
A method for detecting blockage of a measuring tube of a Coriolis flow measuring device, which has at least two measuring tubes. For this, the at least two measuring tubes are excited by at least one exciter to execute mechanical oscillations, mechanical oscillations of the measuring tubes are registered by at least one sensor and at least one measurement signal representing the mechanical oscillations is produced. At least one produced measurement signal is analyzed for the occurrence of a deviation of a resonance frequency of one measuring tube relative to a resonance frequency of the at least one other measuring tube. In case such a deviation occurs, blockage of a measuring tube is established.
Abstract:
A measuring transducer includes: a measuring tube vibrating at least at times and serving for conveying medium to be measured; a counteroscillator, which is affixed to the measuring tube on an inlet-side, to form a first coupling zone, and to the measuring tube on an outlet-side, to form a second coupling zone; an exciter mechanism for driving at least the measuring tube; as well as a sensor arrangement for registering oscillations at least of the measuring tube. During operation, the measuring tube executes, at least at times and/or at least in part, bending oscillations about an imaginary bending oscillation axis, which imaginarily connects the two coupling zones with one another. Additionally, at least a first spring element and a second spring element are included, with each of the at least two spring elements being affixed to the measuring tube and the counteroscillator spaced both from each of the two coupling zones as well as also from the exciter mechanism.
Abstract:
The process meter comprises a sensor that can be mounted in a wall of a vessel for holding or conveying a process medium, and a meter-electronics case mechanically coupled to the sensor. In operation, the electronics case is at least intermittently subjected to vibrations either generated in the sensor itself or transmitted via the sensor. To reduce amplitudes of such vibrations of the electronics case, at least one vibration absorber is affixed to a wall of the electronics case. This vibration absorber is vibrated at least intermittently in order to dissipate vibrational energy taken into the electronic case. By the suppression of such case vibrations, spurious components in the measurement signal can be reduced to the point that a significant improvement in signal-to-noise ratio is obtained.
Abstract:
A measurement pickup, or transducer, includes at least one measuring tube for the conveying of a fluid. The measuring tube has an inlet end and an outlet end and vibrates at least at times. For enabling the fluid to be measured to flow through the measuring tube, the measuring tube communicates, via a first tube segment opening into the inlet end and via a second tube segment opening into the outlet end, with a pipeline connected therewith. For the oscillatable holding of the measuring tube, the measurement pickup further includes a support element having a first end piece containing a passageway for the securement of the first tube segment and having a second end piece containing a passageway for the securement of the second tube segment. Each of the two tube segments extends through its respective one of the two passageways and each of the two passageways has an inner diameter, which is greater than an outer diameter of its associated tube segment, so that an intermediate space is formed between each of the associated tube segments and end pieces. The measurement pickup further includes at least one, preferably metal, first spring element pushed onto one of the two tube segments. The spring element fills the intermediate space formed between tube segment and end piece at least partially, with the spring element being arranged in the intermediate space in such a manner that it contacts, at least sectionally, both its associated tube segment and also its associated end piece in such a manner that it is subjected, at least sectionally, to radially acting, deformation forces. As a result of elastic deformations accompanying such deformation forces, the spring element is held pressed against the associated tube segment and the associated end piece, whereby such tube segment is locked securely in the associated passageway.
Abstract:
The measuring device comprises, for measuring multi phase mixture, a vibratory-type transducer and a measuring device electronics electrically coupled with the vibratory-type transducer. The transducer includes at least one measuring tube inserted into the course of the pipeline. An exciter arrangement acts on the measuring tube for causing the at least one measuring tube to vibrate. A sensor arrangement senses vibrations of the at least one measuring tube and delivers at least one oscillation measurement signal representing oscillations of the measuring tube. Further, the measuring device electronics delivers an excitation current driving the exciter arrangement. The measuring device is adapted to compensating measurement errors, induced due to the presence of multi phase mixture, based on a movin resonator model (MRM).
Abstract:
The viscometer provides a viscosity value (Xη) which represents the viscosity of a fluid flowing in a pipe connected thereto. It comprises a vibratory transducer with at least one flow tube for conducting the fluid, which communicates with the pipe. Driven by an excitation assembly, the flow tube is vibrated so that friction forces are produced in the fluid. The viscometer further includes meter electronics which feed an excitation current (iexc) into the excitation assembly. By means of the meter electronics, a first internal intermediate value (X1) is formed, which corresponds with the excitation current (iexc) and thus represents the friction forces acting in the fluid. According to the invention, a second internal intermediate value (X2), representing inhomogeneities in the fluid, is generated in the meter electronics, which then determine the viscosity value (Xη) using the two intermediate values (X1, X2). The first internal intermediate value (X1) is preferably normalized by means of an amplitude control signal (yAM) for the excitation current (iexc), the amplitude control signal corresponding with the vibrations of the flow tube. As a result, the viscosity value (Xη) provided by the viscometer is highly accurate and robust, particularly independently of the position of installation of the flow tube.
Abstract:
A Coriolis mass flow measuring device includes a vibratory measuring transducer having at least one measuring tube, which has medium flowing through it during operation. In operation, the measuring tube is caused by an exciter arrangement to undergo mechanical oscillations, especially bending oscillations. Additionally, the Coriolis mass flow measuring device includes a sensor arrangement for producing oscillation measurement signals (s1, S2) representing the inlet-end and outlet-end oscillations of the measuring tube. Measuring device electronics controlling the exciter arrangement produces an exciter current (iexc) and an intermediate value (X′m) derived from the oscillation measurement signals (s1, s2). This intermediate value represents an uncorrected mass flow. Derived from the exciter current and/or from a component of the exciter current (iexc), an intermediate value (X2) is produced, which corresponds to a damping of the oscillations of the measuring tube. This damping is especially a function of an apparent viscosity, and/or a viscosity-density product, of the medium guided in the measuring tube. Furthermore, a correction value (XK) is produced for the intermediate value (X′m) utilizing the intermediate value (X2) and a viscosity measurement value (Xη) determined initially or during operation. The viscosity measurement value (Xη) corresponds to a viscosity of the medium guided in the measuring tube and/or to a predetermined reference viscosity. On the basis of the intermediate value (X′m) and the correction value (XK), the measuring device electronics then produces an exact mass flow rate measurement value (Xm).
Abstract:
An inline measuring device includes a vibration-type measurement pickup having at least one measuring tube, which has a medium to be measured flowing through it during operation. The measuring tube is made by means of an exciter arrangement to execute, at least at times and/or at least in part, lateral oscillations and, at least at times and/or at least in part, torsional oscillations about an imaginary measuring tube longitudinal axis. The torsional oscillations alternate with the lateral oscillations or are, at times, superimposed thereon. Also included is a sensor arrangement for producing oscillation measurement signals correspondingly representing oscillations of the measuring tube. Measuring device electronics controlling the exciter arrangement generates, by means of at least one of the oscillation measurement signals and/or by means of the exciter current, at least at times, at least one measured value, which represents the at least one physical quantity to be measured. Additionally, the measuring device electronics also determines a first intermediate value, which corresponds to the lateral current component of the exciter current serving to maintain the lateral oscillations of the measuring tube and/or to a damping of the lateral oscillations of the measuring tube, as well as a second intermediate value, which corresponds to a torsional current component of the exciter current serving to maintain the torsional oscillations of the measuring tube and/or to a damping of the torsional oscillations of the measuring tube. With the goal of producing the measured value at high accuracy, such value is determined also taking into consideration these two intermediate values. The measured value obtained in this way is distinguished especially by high accuracy also in the case of media of two, or more, phases.
Abstract:
The viscometer provides a viscosity value (Xη) which represents the viscosity of a fluid flowing in a pipe connected thereto. It comprises a vibratory transducer with at least one flow tube for conducting the fluid, which communicates with the pipe. Driven by an excitation assembly, the flow tube is vibrated so that friction forces are produced in the fluid. The viscometer further includes meter electronics which feed an excitation current (iexc) into the excitation assembly. By means of the meter electronics, a first internal intermediate value (X1) is formed, which corresponds with the excitation current (iexc) and thus represents the friction forces acting in the fluid. According to the invention, a second internal intermediate value (X2), representing inhomogeneities in the fluid, is generated in the meter electronics, which then determine the viscosity value (Xη) using the two intermediate values (X1, X2). The first internal intermediate value (X1) is preferably normalized by means of an amplitude control signal (yAM) for the excitation current (iexc), the amplitude control signal corresponding with the vibrations of the flow tube. As a result, the viscosity value (Xη) provided by the viscometer is highly accurate and robust, particularly independently of the position of installation of the flow tube.