Coriolis Mass Flow Meter Magnetic Field 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 sensor assembly that calculates characteristic number values from vibration measurement signals to detect changes in sensor asymmetry, allowing for the detection of external magnetic fields and their impact on measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional Coriolis mass flow meters use electrodynamic vibration sensors, then measurement capability is enabled, but external magnetic fields cause phase errors and reduce measurement accuracy
Solution Approach 1:
The system continuously monitors the amplitude of vibration measurement signals and calculates characteristic numbers to detect changes in sensor asymmetry. This feedback mechanism allows the system to identify when external magnetic fields are interfering with measurements and triggers appropriate responses to maintain measurement accuracy.
Solution Approach 2:
The patent replaces electrodynamic vibration sensors with mechanical vibration sensors that do not rely on electromagnetic fields for operation. This substitution eliminates the vulnerability to external magnetic field interference while maintaining the ability to detect vibration signals for mass flow measurement.
2Reliability
If the system monitors vibration signal amplitudes to detect magnetic field interference, then measurement reliability is improved, but device complexity increases
Solution Approach 1:
The system uses the existing vibration measurement signals to simultaneously perform both mass flow measurement and magnetic field interference detection. By calculating characteristic numbers from the same signals already being processed for measurement, the system achieves enhanced reliability without requiring separate dedicated monitoring hardware.
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 solution enables timely detection and reporting of external magnetic field influences, improving measurement accuracy and reliability by distinguishing asymmetrical changes in vibration sensor signals that indicate external magnetic field interference.
Implementation Method 1
The first vibration sensor (51) is configured to convert vibrational movements of the at least one measurement tube (10) at a first measurement point into an electric first vibration measurement signal (s1)
Implementation Method 2
the exciter assembly is configured to convert electric power fed to the exciter assembly into mechanical power that produces forced mechanical vibrations of the at least one measurement tube (10)
Implementation Method 3
external magnetic fields, which can cause phase errors and reduce measurement accuracy
Data Source
AI summary
A Coriolis mass flow meter comprises a vibration element, an exciter assembly, a sensor assembly, and an electronic transformer circuit electrically coupled to the exciter assembly and the sensor assembly. The vibration element is contacted by the flowing fluid. The exciter assembly is designed to convert electric power into mechanical power to produce mechanical vibrations of the vibration element. The transformer circuit generates an electric driver signal and feeds electric power to the exciter assembly. The vibration element mechanically vibrates with a vibration frequency specified by the electric driver signal. The sensor assembly has two electrodynamic vibration sensors designed to convert vibrational movements of the vibration element at a first or at a second measurement point into electric vibration measurement signals having an AC voltage component with a frequency and with an amplitude based on the frequency and on a magnetic flux flowing through the respective vibration sensor.