Vibronic Sensor Stiffness Control via Giant Delta-E Effect
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Solution Overview
Problem
Vibronic sensors with a single rod oscillatable unit face challenges in maintaining signal stability and adjusting natural resonant frequencies due to changes caused by buildup or corrosion, making it difficult to distinguish between amplitude reductions from filling levels and other factors.
Innovation Solution
Incorporating a material with a giant delta E effect, such as amorphous ferromagnetic materials, and using a magnetic field to vary the stiffness of the oscillating rods, allowing for continuous adjustment of resonant frequencies without contact with the medium, thereby maintaining signal stability and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a single rod oscillatable unit is used instead of a fork, then medium jamming between fork tines is avoided, but signal stability and force compensation deteriorate
Solution Approach 1:
The single rod oscillatable unit is divided into two separate oscillating rods (first and second rods) that oscillate in opposite directions. This segmentation allows each rod to independently interact with the medium while maintaining overall system stability and preventing medium jamming issues.
Solution Approach 2:
The two oscillating rods are designed to oscillate in opposite directions with equal amplitude, creating a counterbalancing effect that compensates for forces acting on the clamping area. This anti-weight principle ensures that reaction forces are minimized while maintaining signal stability.
2Power
If the natural resonant frequencies of two oscillating rods are coordinated, then maximum oscillation amplitude is achieved, but build-up or corrosion on the outer rod changes its resonant frequency, causing coordination loss
Solution Approach 1:
The stiffness of the oscillating rods is made dynamically adjustable through a control element that can modify the rod properties in real-time. This allows the system to adapt to changes in mass or environmental conditions and maintain resonant frequency coordination for maximum oscillation amplitude.
Solution Approach 2:
The electronics unit continuously monitors the oscillation characteristics and adjusts the control element to maintain proper frequency coordination between the two rods. This feedback mechanism ensures that resonant frequency alignment is preserved despite build-up or corrosion on the outer rod.
3Measurement precision
If a control element with magnetic field actuation is used to adjust rod stiffness, then resonant frequency can be tuned, but power consumption increases
Solution Approach 1:
The control element utilizes the giant delta E effect to achieve large changes in rod stiffness with minimal magnetic field strength. By selecting materials with giant delta E effect, the system can tune resonant frequencies precisely while requiring only small magnetic fields, thus minimizing power consumption.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables a power-saving vibronic sensor with improved signal stability and accuracy, capable of distinguishing between filling level changes and other factors, even in liquids, by using small magnetic fields that reduce power consumption and maintain resonant frequency coordination.
Implementation Method 1
Incorporating a material with a giant delta E effect, such as amorphous ferromagnetic materials, and using a magnetic field to vary the stiffness of the oscillating rods
Implementation Method 2
a piezoelectric drive or an electromagnetic drive
Implementation Method 3
a piezoelectric drive or an electromagnetic drive
Implementation Method 4
the natural resonant frequency of which is determined by the mass moment of inertia of the oscillating rod and the spring constant of the elastic holding part
Data Source
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AI summary
The invention relates to a vibronic sensor (1) for monitoring a process variable of a medium (2) in a container (3), at least comprising a unit (4) that can vibrate mechanically, a driving/receiving unit (5), and an electronic unit (6), wherein the unit (4) that can vibrate mechanically has two vibration bars (7, 8) and a control element (13), which is mechanically connected to at least one of the vibration bars (7, 8) and the stiffness of which can be varied, wherein at least one first, outer vibration bar (7) is tubular and coaxially surrounds a second, inner vibration bar (8), wherein each of the two vibration bars (7, 8) is fastened to a common support (9) in such a way that the vibration bar can perform vibrations transversely to the longitudinal direction of the vibration bar, wherein the driving/receiving unit (5) is designed to excite the two vibration bars (7, 8) to oppositely directed, transverse, mechanical, resonant vibrations by means of an electrical excitation signal (Ua) and to receive the vibrations of the unit (4) that can vibrate mechanically and to convert said vibrations into an electrical reception signal (Ue), wherein the electronic unit (6) is designed to set the stiffness of the control element (13) and to determine the at least one process variable at least from the electrical reception signal (Ue), and wherein the control element (13) comprises at least one component (15) composed of a material that has a giant delta-E effect.