Dual Flow Meter Zero Offset Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Coriolis flowmeters experience zero flow instability, leading to inconsistent flow rate measurements between multiple flow meters, even when the actual flow rates are the same, due to varying meter zeroes, which prior methods fail to account for.
Innovation Solution
A dual flow meter system is implemented where a second flow meter with lower zero flow instability corrects the measurements of a first flow meter with higher zero flow instability by calculating and applying the difference in previously measured flow rates when both meters are in series, extending the measurement range to low flow rates where signals cannot be distinguished from noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple flow meters are used to measure flow rates, then measurement coverage is improved, but measurement consistency deteriorates due to zero flow instability
Solution Approach 1:
The system continuously monitors flow rates from multiple flow meters and uses feedback control to adjust measurements. When zero flow instability is detected in one flow meter, the system automatically compensates by referencing measurements from other flow meters, ensuring consistent and accurate flow rate measurements across all operating conditions.
2Adaptability or versatility
If a flow meter operates at low flow rates, then measurement range is improved, but measurement accuracy deteriorates because measurement signal cannot be distinguished from noise
Solution Approach 1:
The system combines measurements from multiple flow meters to determine the corrected measured flow rate. By merging data from several flow meters including those with lower zero flow instability, the system achieves accurate measurements at low flow rates where individual flow meter signals would otherwise be indistinguishable from noise.
3Measurement precision
If flow rate measurements are corrected using differential zero offset between meters, then measurement consistency is improved, but applicability deteriorates because both meters must be Coriolis type
Solution Approach 1:
The system determines a corrected measured flow rate by comparing measurements from multiple flow meters of different types (Coriolis, positive displacement, turbine, vortex, electromagnetic, ultrasonic). This universal approach allows any combination of flow meters to be used together, eliminating the limitation that both meters must be Coriolis type while maintaining measurement consistency through zero flow instability compensation.
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 provides more accurate flow rate measurements by compensating for zero flow instability in the first flow meter, ensuring consistent readings across multiple flow meters and extending the measurement range to previously unmeasurable low flow rates.
Implementation Method 1
a magnet and an opposing drive coil have received great success in the flowmeter industry. An alternating current is passed to the drive coil for vibrating the conduit(s) at a desired conduit amplitude and frequency
Implementation Method 2
Pickoffs on the conduit(s) produce sinusoidal signals representative of the motion of the conduit(s). Signals output from the pickoffs are processed to determine the time delay between the pickoffs
Implementation Method 3
As material begins to flow through the conduit(s), Coriolis forces cause each point along the conduit(s) to have a different phase
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of determining a corrected measured flow rate is provided. The method includes measuring a flow rate with a first flow meter, measuring a flow rate with a second flow meter, the second flow meter being fluidly coupled to the first flow meter in series, and correcting the measured flow rate of the first flow meter with the measured flow rate of the second flow meter.