Capacitive Point Source Sensor for Potable Water Level Detection

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Solution Overview

Problem

Existing water level sensors in aircraft containers for potable water are prone to corrosion, which affects their accuracy and reliability in detecting liquid levels.

Innovation Solution

A capacitive point source sensor system with a main body featuring conductive contacts and an insulator, such as a glass or polymer coating, that reduces corrosion and accurately detects liquid levels by varying capacitance based on proximity to water, using alternating current signals and a controller to determine liquid presence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional water level sensors are used in aircraft potable water containers, then liquid level detection function is provided, but corrosion occurs affecting accuracy and reliability

Engineering Contradiction:
Improvesensor reliabilityVSAvoidcorrosion
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an insulator as an intermediary material between the sensor components and the potable water. This insulator prevents direct contact between the sensor elements and water, thereby eliminating corrosion while maintaining the sensor's ability to detect liquid levels through capacitive coupling through the insulator material.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces conventional mechanical or direct-contact electrical sensors with a capacitive sensing system. This substitution allows the sensor to detect liquid levels through electromagnetic field interactions rather than direct physical contact, eliminating the mechanical wear and chemical corrosion issues inherent in traditional sensor designs.

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

2Measurement precision

If sensors are installed in potable water containers to detect water levels, then liquid level measurement is enabled, but corrosion affects measurement accuracy

Engineering Contradiction:
Improvewater level detection accuracyVSAvoidcorrosion
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The insulator serves as a mediator that preserves measurement accuracy while preventing corrosion. The capacitive sensing mechanism measures changes in electrical field properties caused by the presence or absence of liquid, allowing accurate level detection without direct sensor-water contact that would cause corrosive degradation and accuracy loss.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sensor assembly utilizes composite material structures, combining conductive elements for sensing with insulating materials for corrosion protection. This composite approach integrates the functional requirements of electrical sensing with the protective requirements of corrosion resistance, maintaining measurement precision over extended service life.

Inventive Principle:
Principle #40Composite materials

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

The system effectively detects liquid levels in aircraft containers with reduced corrosion risk, providing accurate and reliable measurements without affecting the potable water, enhancing the monitoring of water levels in aircraft storage systems.

Implementation Method 1

capacitive point source sensor for detecting presence of a liquid... varying capacitance based on proximity to water

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3901589B1Capacitive point source level sensor for potable water systems
Publication Date: 2024.01.17 GOODRICH CORP
  • EP3901589B1 patent drawingFigure 1
  • EP3901589B1 patent drawingFigure 2
  • EP3901589B1 patent drawingFigure 3A~3B

AI summary

A capacitive point source sensor for detecting presence of a liquid includes a main body (300) having a sensor end (302) and an outer end (304), the main body being configured to be coupled to and at least partially inserted through a container (102) of the liquid. The sensor further includes two conductive contacts (306, 308) located on the sensor end of the main body. The sensor further includes an insulator (320) enclosing the two conductive contacts.