Vibronic Fork Sensor Impedance Tuning for Vibration Symmetry
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Solution Overview
Problem
Existing vibronic sensors face challenges in achieving high measurement accuracy due to slight deviations in the geometry of vibrating elements, which affect the vibration behavior and hinder precise determination of process variables.
Innovation Solution
A device with adjustable impedance elements connected in series to piezoelectric elements in the vibrating fork, allowing for symmetrization of the vibrating elements by adjusting impedance to match their vibration behavior, ensuring identical performance without mechanical alterations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If mechanical symmetrization of vibrating elements is performed through individual machining, then measurement precision is improved, but device complexity and manufacturing time increase
Solution Approach 1:
The patent replaces the mechanical symmetrization process (individual machining of vibrating elements) with an electrical adjustment system. Adjustable impedance elements are integrated into the drive/receive unit to electrically balance the vibration behavior of the vibrating elements, eliminating the need for complex mechanical machining operations while achieving the same symmetrization effect.
Solution Approach 2:
The patent changes the electrical parameters (impedance values) of the drive/receive unit to compensate for geometric deviations in the vibrating elements. By adjusting the impedance of individual piezoelectric elements or electromagnetic coils, the vibration characteristics of each vibrating element can be fine-tuned to achieve symmetry without mechanical intervention.
2Measurement precision
If individual machining of vibrating elements is performed to correct geometric deviations, then measurement precision is improved, but manufacturing time increases
Solution Approach 1:
The patent incorporates adjustable impedance elements during the manufacturing process of the drive/receive unit, allowing symmetrization to be performed as part of the initial assembly rather than as a separate post-processing step. This preliminary integration of adjustment capabilities reduces the total manufacturing time by eliminating iterative machining cycles.
Solution Approach 2:
By replacing time-consuming mechanical machining operations with electrical impedance adjustments, the patent significantly reduces the time required for symmetrization. Electrical parameter adjustments can be made quickly without removing material or requiring complex machining setups.
3Measurement precision
If geometric symmetry of vibrating elements is achieved through machining, then measurement precision is improved, but ease of manufacture decreases
Solution Approach 1:
The patent replaces difficult mechanical machining operations with simple electrical component adjustments. The adjustable impedance elements can be tuned using standard electronic adjustment techniques, which are generally easier and more versatile than precision mechanical machining, especially for correcting small geometric deviations.
Solution Approach 2:
The patent transforms the symmetrization problem from a mechanical geometry correction task into an electrical parameter adjustment task. By changing electrical impedance values, manufacturers can compensate for geometric variations without requiring high-precision machining capabilities, thereby simplifying the manufacturing process.
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 enhances measurement accuracy by precisely matching the vibration behavior of the vibrating elements, improving sensor performance with minimal effort and complexity.
Implementation Method 1
at least one first piezoelectric element which is at least partly arranged in the first vibrating element
Implementation Method 2
receive the mechanical vibrations of the vibratable unit and convert same into a first reception signal
Implementation Method 3
The electronic unit has at least one adjustable impedance element, which is connected in series to the first piezoelectric element
Data Source
AI summary
A device for determining and/or monitoring a process variable of a medium comprises a sensor unit with a mechanically vibrating fork having a first and a second vibrating element and having a first piezoelectric element arranged in the first vibrating element. An electronic unit of the device is designed to excite mechanical vibrations in the mechanically vibratable unit, receive the mechanical vibrations of the vibratable unit and convert same into a first reception signal, generate the excitation signal on the basis of the first reception signal such that there is a specifiable phase shift between the excitation signal and the first reception signal, and ascertain the process variable using the first reception signal. The electronic unit has an adjustable impedance element connected in series to the first piezoelectric element.