Inductive Transducer Displacer Position Detection

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Solution Overview

Problem

Existing flowmeter proving systems face challenges in accurately determining the dynamic position of a displacer across the face of a transducer, especially at extreme temperatures and with dynamic translation, leading to less than desired accuracy and limited operational ranges.

Innovation Solution

The use of inductive transducers with signal analyzers to detect changes in inductance caused by a magnetic target's movement, allowing for precise determination of displacer velocity and position, and employing signal conditioning modules to generate and condition output signals for accurate position detection over a wide range of temperatures and velocities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional detector switches are used to determine displacer position, then the system structure is simple, but the measurement precision deteriorates at extreme temperatures and dynamic velocities

Engineering Contradiction:
Improvedisplacer position detection accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical detector switches with an inductive transducer system that uses electromagnetic fields to detect displacer position. The inductive transducer measures changes in inductance caused by the magnetic target's movement, eliminating mechanical contact and improving reliability at extreme temperatures and high velocities while maintaining reasonable system complexity through electronic signal processing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If mechanical detector switches are used, then the device complexity is low, but the reliability deteriorates under dynamic flow conditions and extreme temperatures

Engineering Contradiction:
Improveposition detection reliabilityVSAvoiddetection system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical detector switches with an inductive transducer system that uses electromagnetic fields to detect displacer position. The inductive transducer measures changes in inductance caused by the magnetic target's movement, eliminating mechanical contact and improving reliability at extreme temperatures and high velocities while maintaining reasonable system complexity through electronic signal processing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If inductive transducers with signal analyzers are used to detect displacer position, then the measurement precision improves, but the device complexity increases

Engineering Contradiction:
Improvedisplacer position detection accuracyVSAvoidsignal detection and processing system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a signal conditioning module as an intermediary between the inductive transducer and the measurement system. This module processes the raw inductance change signals, filtering and conditioning them to provide accurate position information while reducing the complexity burden on the overall system by handling signal processing in a dedicated intermediate stage.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 precise dynamic position detection of the displacer, enhancing the accuracy of flowmeter calibration and proving systems, ensuring reliable measurements across a broad temperature range from -230°C to 425°C, and supporting standards like API and ISO for custody transfer of fluids.

Implementation Method 1

Inductance of an inductive transducer coupled to the flow tube changes based on proximity of a magnet target of the displacer to the transducer

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentEP2665996B1Apparatus and method for determing displacer position in a flowmeter prover
Publication Date: 2018.08.29 DANIEL MEASUREMENT & CONTROL INC
  • EP2665996B1 patent drawingFigure 1
  • EP2665996B1 patent drawingFigure 2
  • EP2665996B1 patent drawingFigure 3

AI summary

Apparatus and methods for proving a flowmeter. In one embodiment, a flowmeter prover includes a flow tube, a displacer, and a signal analyzer. The displacer is moveable in a flow passage of the flow tube. A magnetic target is disposed on the displacer. One or more inductive transducers are disposed on the flow tube and configured to detect the magnetic target as the displacer moves in the flow tube. The signal analyzer is configured to detect a maximum slope of rising and falling edges of a signal generated by the transducer responsive to the magnetic target traversing the transducer. The signal analyzer is further configured to determine displacer velocity based on the detected maximum slope.