Process Control Sensor Using Capacitance for Solution Concentration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing industrial process devices face ambiguity in determining solution concentration due to non-single-valued conductivity measurements, where a single conductivity value can correspond to multiple concentration values.

Innovation Solution

The solution concentration is determined by measuring capacitance, which is single-valued with respect to concentration, using a transmitter that applies an electric field and measures the capacitance of the solution, allowing for the elimination of ambiguity by correlating dielectric constant and capacitance values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conductivity measurement is used to determine solution concentration, then measurement capability is provided, but measurement precision deteriorates due to non-single-valued relationship causing ambiguity

Engineering Contradiction:
Improveconcentration determination precisionVSAvoidconcentration information ambiguity
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent changes the measurement parameter from conductivity to capacitance. Capacitance provides a single-valued relationship with concentration, eliminating the ambiguity inherent in conductivity measurements. The transmitter measures capacitance of the solution directly, and this parameter changes fundamentally resolve the information loss problem.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If capacitance measurement is used to determine solution concentration, then measurement precision improves through single-valued relationship, but device complexity increases compared to simple conductivity measurement

Engineering Contradiction:
Improveconcentration determination precisionVSAvoidtransmitter measurement capability
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The transmitter is designed to measure multiple electrical parameters (capacitance, conductance, impedance) using a unified measurement architecture. This multi-functionality allows the device to perform capacitance-based concentration determination while maintaining measurement flexibility and reducing overall system complexity through a single integrated instrument.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 method provides unambiguous solution concentration determinations by leveraging the consistent relationship between dielectric constant and capacitance, enabling accurate concentration measurements in industrial processes.

Implementation Method 1

industrial process control transmitter... measures capacitance of solution

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

measuring capacitance... correlating dielectric constant and capacitance values

Methodology Applied
Scientific EffectDielectric constant: Dielectric Permittivity

Data Source

PatentEP3438652B1Industrial process control sensor for determining solution concentration
Publication Date: 2023.02.22 SCHNEIDER ELECTRIC SYSTEMS USA INC
  • EP3438652B1 patent drawingFigure 1A
  • EP3438652B1 patent drawingFigure 1B
  • EP3438652B1 patent drawingFigure 2

AI summary

Automated measurement of fluid solution capacitance in industrial processes to determine solution concentration. Industrial process control transmitter (100) determines solution concentration directly from measured solution capacitance and confirms concentration determinations based on solution conductivity. The industrial process control transmitters include terminals embodied in wire coils (drive coil (106), response coil (108)) and/or metallic plates integrated in pipe (112) or in direct contact with process solution, at least one processor (104), and at least one computer readable memory device.