Coriolis Flow Meter Magnetic Interference Detection
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Solution Overview
Problem
Conventional Coriolis mass flow meters face challenges in accurately measuring mass flow due to interference from external magnetic fields, which can cause phase errors and reduce measurement accuracy.
Innovation Solution
The Coriolis mass flow meter incorporates an electronic transformer circuit with electrodynamic vibration sensors and a detection system that evaluates harmonic components of vibration measurement signals to detect deviations caused by external magnetic fields, allowing for timely reporting of measurement inaccuracies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional Coriolis mass flow meters use electrodynamic vibration sensors, then measurement capability is provided, but external magnetic fields cause phase errors and reduce measurement accuracy
Solution Approach 1:
The patent applies FFT analysis to detect harmonic components in the vibration measurement signals. These harmonic components, which are normally considered interference or noise, are actually useful indicators for detecting external magnetic field effects. By analyzing the spectral content and identifying specific harmonic patterns, the system converts the harmful magnetic field interference into a detectable signal characteristic that enables compensation or correction measures.
Solution Approach 2:
The patent implements a feedback mechanism where the measured vibration signals are continuously analyzed using FFT, and the detected harmonic components trigger corrective actions. The system monitors the phase relationships and spectral content, and when external magnetic field interference is detected through characteristic harmonic patterns, it adjusts the measurement or signals an error condition, creating a closed-loop feedback system that maintains measurement accuracy despite external disturbances.
2Adaptability or versatility
If the flow meter operates in environments with external magnetic fields, then operational versatility is maintained, but phase errors occur and measurement accuracy deteriorates
Solution Approach 1:
The patent enables the flow meter to operate in magnetically noisy environments by using FFT analysis to detect and identify external magnetic field interference through harmonic components. Rather than avoiding such environments, the system adapts to them by converting the magnetic field effects into detectable spectral signatures, allowing the meter to maintain operational versatility while compensating for the accuracy degradation through signal processing and error detection.
3Reliability
If vibration measurement signals are analyzed without considering harmonic components, then device complexity is reduced, but external magnetic field interference remains undetected
Solution Approach 1:
The patent replaces complex mechanical or hardware-based filtering and detection mechanisms with software-based FFT signal processing. Instead of using additional sensors, shields, or mechanical filters to detect and compensate for magnetic field interference, the system uses digital signal processing algorithms to analyze the spectral content of existing vibration signals, identifying harmonic components that indicate external magnetic field effects. This substitution reduces physical device complexity while enhancing detection capability.
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 the detection and reporting of external magnetic field interference, thereby maintaining measurement accuracy and reducing undetected errors in mass flow measurements.
Implementation Method 1
an electrodynamic first vibration sensor (51) and at least one electrodynamic second vibration sensor (52)... The first vibration sensor (51) is configured to convert vibration movements of the at least one measurement tube (10)... into an electrical first vibration measurement signal (s1)
Implementation Method 2
an exciter assembly (41)... configured to convert electric power fed to the exciter assembly (41) into mechanical power causing forced mechanical vibrations of the at least one measurement tube (10)
Implementation Method 3
the transformer circuit (US) is configured to determine, on the basis of the first and second vibration measurement signals (s1, s2), characteristic number values for at least one sensor characteristic number (SK1), such that said sensor characteristic number (SK1) characterizes at least one of the first and second harmonic components
Data Source
AI summary
A Coriolis mass flow meter comprises a transformer circuit configured to receive and analyze vibration measurement signals to determine mass flow measurement values which represent a mass flow of a fluid and to determine characteristic number values for at least one sensor characteristic number, which characterizes and/or is based on at least one harmonic component of at least one of the vibration measurement signals, wherein each vibration measurement signal includes a useful component, having a frequency corresponding to a drive frequency with an amplitude based on a respective magnetic flux through a respective vibration sensor of the flow meter, and a harmonic component having a frequency corresponding to a whole-number multiple of the drive frequency and an amplitude based on the respective magnetic flux.