Coriolis Mass Flowmeter Channel Phase Shift Compensation
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Solution Overview
Problem
Coriolis mass flowmeters face challenges in achieving high measurement accuracy due to phase shifts caused by measurement channels, which are difficult to stabilize without significant design and cost-intensive efforts, leading to unsatisfactory short-term accuracy.
Innovation Solution
The method involves alternately routing primary measurement signals through multiple measurement channels to the control and evaluation unit, calculating compensation values by averaging the obtained values, and using these values to determine the derived secondary variable, such as mass flow, thereby minimizing interference from measurement channel phase shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If measurement channels are stabilized through strict compliance with reference conditions, then measurement precision is improved, but device complexity and cost increase significantly
Solution Approach 1:
The patent applies feedback by measuring the actual transmission behavior of measurement channels and using this information to calculate compensation values. The system continuously monitors phase shifts and other transmission characteristics, then adjusts the measurement results accordingly, creating a closed-loop system that maintains accuracy without requiring overly complex design constraints
Solution Approach 2:
The patent changes the approach from stabilizing physical parameters (temperature, mechanical stress) through design constraints to stabilizing electrical/signal parameters through post-processing. By measuring actual transmission characteristics and applying compensation calculations, the system transforms the problem from a design-stage constraint to an operational-stage correction
2Measurement precision
If measurement channels are stabilized through strict compliance with reference conditions, then measurement precision is improved, but production cost increases significantly
Solution Approach 1:
The feedback mechanism measures actual transmission behavior and applies compensation, replacing the need for expensive design-stage stabilization measures. This allows standard, lower-cost measurement channels to be used while achieving high precision through software-based correction
Solution Approach 2:
The patent effectively replaces expensive, highly stable measurement channel hardware with cheaper, standard components that can be compensated through calculation. The compensation values act as a virtual correction that allows the use of less expensive physical components
3Measurement precision
If measurement channels are stabilized through strict compliance with reference conditions, then measurement precision is improved, but measurement duration increases due to short-term stability requirements
Solution Approach 1:
The patent performs preliminary measurement of the transmission behavior characteristics (phase shifts, amplitude ratios) and stores these as compensation values. This preliminary characterization allows subsequent measurements to be quickly corrected without requiring extended stabilization periods, as the compensation data is pre-established
Solution Approach 2:
The continuous feedback mechanism allows the system to maintain accuracy over time by applying real-time compensation based on measured transmission characteristics, eliminating the need for long stabilization periods that would otherwise be required to ensure short-term stability
4Measurement precision
If multiple measurement channels are used with alternating signal routing, then measurement precision is improved through compensation, but device complexity increases
Solution Approach 1:
The patent merges the functions of multiple measurement channels by alternately routing signals through them and combining the results through compensation calculations. This allows the system to use redundancy for improved accuracy while managing complexity through unified control logic that handles multiple channels in a systematic way
Solution Approach 2:
The control unit is designed with universal functionality to handle multiple measurement channels, performing the same measurement and compensation operations across different channels. This multi-functional approach allows the system to achieve improved precision through channel comparison while avoiding the need for separate dedicated circuits for each channel
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 allows for accurate and reliable measurement of mass flow and other diagnostic parameters by equalizing the transmission behavior of measurement channels, reducing measurement errors and ensuring long-term precision.
Implementation Method 1
at least one measuring tube through which a medium flows is excited by a vibration generator to oscillate
Data Source
Figure 1
Figure 2
Figure 3a~3b
AI summary
The invention relates to a method for operating a Coriolis mass flow measuring device (1), wherein said Coriolis mass flow measuring device (1) comprises at least one measuring pipe through which a medium flows, at least one vibration generator (2a, 2b), at least a first vibration sensor (3a), at least a second vibration sensor (3b) and at least a control and analyzing unit (4). Excitation signals (UDae, UDbe) can be guided from the control and analyzing unit (4) to the vibration generator (2a, 2b) via at least one excitation channel (Cha1, Cha2), wherein a first interested primary measurement signal (Va) can be guided from the first vibration generator (3a) to the control and analyzing unit (4) via at least a first measurement channel (Ch1) and a second interested primary measurement signal (Vb) can be guided from the second vibration generator (3b) to the control and analyzing unit (4) via at least a second measurement channel (Ch2). The detection of the relevant measurement variables or diagnosis parameters is achieved with increased accuracy and security in that the control and analyzing unit (4) calculates, at least indirectly and in a ratiometric manner, at least a derived secondary variable (m), based on the primary measurement signals (Vag, Vbg) transmitted via the measurement channels (Ch1, Ch2, Chn), wherein the interested primary measurement signals (Va, Vb') are guided alternately to the control and analyzing unit (4) via the different measurement channels (Ch1, Ch2, Chn) and wherein, based on the various values (Vag1, Vag2, Vagn; Vbg1, Vbg2, Vbgn) obtained from the different measurement channels (Ch1, Ch2, Chn) regarding the transmitted primary measurement signals (Vag, Vbg), compensation values (Vam, Vbm) of the transmitted primary measurement signals are calculated and said compensation values (Vam, Vbm) are used as a basis for the calculation of the derived secondary variable (m).