Mixture State Determination Using Impedance Equivalent Circuits

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Solution Overview

Problem

Existing methods for determining the state of mixtures with insoluble solid matters in liquid, such as sedimentation tests, are time-consuming and require complex manual observations, making it difficult to easily derive an index for specifying the state of the mixture.

Innovation Solution

A state determination apparatus and method that applies an AC signal to the mixture, measures impedance at various frequencies, sets an equivalent circuit with parallel circuits representing solid matter electrical components, and calculates parameters to derive an index for specifying the mixture's state using equivalent circuit analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a sedimentation test is used to determine particle diameter distribution, then the measurement can be performed using natural gravity or centrifugal force, but it takes a long time for sedimentation to stabilize and requires complex manual observation

Engineering Contradiction:
Improveparticle diameter distribution measurementVSAvoidsedimentation stabilization time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical sedimentation process with electrical impedance measurement. Instead of allowing particles to settle under gravity or centrifugal force and manually observing the process, the invention applies AC signals at multiple frequencies to measure impedance, which directly reflects particle distribution in the liquid. This substitution of mechanical sedimentation with electrical measurement eliminates the time-consuming stabilization period and manual observation requirements while maintaining measurement accuracy for particle diameter distribution.

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

Solution Approach 2:

The invention changes the measurement parameter from physical observation of sedimentation height to electrical impedance measurement. By measuring impedance at multiple frequencies and analyzing the frequency characteristics, the system can derive particle diameter distribution without waiting for sedimentation to stabilize. The parameter change from mechanical position measurement to electrical property measurement enables rapid state determination.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If a sedimentation test is used to determine particle diameter distribution, then the measurement can be performed using natural gravity or centrifugal force, but it requires complex manual observation by measurers

Engineering Contradiction:
Improveparticle diameter distribution measurementVSAvoidobservation operation
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces manual visual observation with automated electrical impedance measurement. The system applies AC signals through electrodes and automatically measures impedance across multiple frequencies, eliminating the need for measurers to visually track sedimentation boundaries. The computer automatically analyzes the impedance data to determine particle distribution, making the operation simple and repeatable without requiring trained observers.

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

Solution Approach 2:

The measurement system performs self-analysis through automated impedance measurement and computer-based data processing. The system automatically derives particle diameter distribution from impedance frequency characteristics without requiring manual intervention for observation or calculation. This self-service capability eliminates complex manual operations while maintaining measurement precision.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If impedance measurement with equivalent circuit analysis is used, then the index for specifying mixture state can be derived easily, but the system requires application of AC signal and mathematical modeling

Engineering Contradiction:
Improveindex derivation operationVSAvoidmeasurement system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent introduces an equivalent circuit model as an intermediary between impedance measurement and particle state determination. The system measures impedance at multiple frequencies, fits the data to an equivalent circuit model with parallel RC elements, and derives particle distribution from the circuit parameters. This intermediary modeling approach simplifies the derivation process by providing a mathematical framework that directly relates measurable impedance to particle characteristics, making the operation easy despite the underlying system complexity.

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

Enables easy derivation of an index for specifying the state of the mixture, reducing time and complexity by using impedance measurement and equivalent circuit analysis to determine physical and electric characteristics.

Implementation Method 1

measurement means configured to measure an impedance of the mixture for every frequency of the AC signal based on a response signal flowing through the mixture when the AC signal is applied

Methodology Applied
Scientific EffectElectrical Impedance: Electrical Resistance

Data Source

PatentEP3951373B1State determination apparatus, state determination method, and storage medium
Publication Date: 2025.12.03 HIOKI DENKI KK
  • EP3951373B1 patent drawingFigure 1
  • EP3951373B1 patent drawingFigure 2
  • EP3951373B1 patent drawingFigure 3A~3B

AI summary

A state determination apparatus includes: electrodes configured to apply AC signal to a mixture; measurement means configured to measure an impedance of the mixture for every frequency of the AC signal based on a response signal flowing through the mixture when the AC signal is applied; setting means configured to set an equivalent circuit including one or a plurality of parallel circuit(s) based on element(s) corresponding to electrical component(s) of a solid matter; calculating means configured to calculate a parameter of the parallel circuit by executing an equivalent circuit analysis for approximating impedance of the equivalent circuit to the impedance of the mixture; and derivation means configured to derive an index for specifying a state of the mixture based on the parameter of the parallel circuit.