Insulated Electrode Sensor for Oil Resistance Measurement

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Solution Overview

Problem

Existing sensor devices measuring liquid properties face durability issues due to electrode corrosion and high manufacturing costs when trying to prevent corrosion, which affects the accuracy of resistance measurements.

Innovation Solution

A sensor device with a first electrode pair covered by an insulating protective film, using AC current for resistance measurement, and incorporating a storage part for parasitic capacitance to improve durability and accuracy without increasing manufacturing costs, and optionally including error correction and temperature compensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an electrode pair is used to measure the resistance of liquid, then the resistance measurement function is achieved, but the electrode pair is corroded by the liquid reducing durability

Engineering Contradiction:

ImprovedurabilityVSAvoidcorrosion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

An insulating protective film is introduced as an intermediary layer between the electrode pair and the liquid. This film prevents direct contact between the liquid and electrode, eliminating corrosion while allowing electrical measurement through the insulating layer. The parasitic capacitance of this film is measured and compensated to maintain measurement accuracy.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If carbon nanotubes or diamond-like carbon are used to form the electrode pair for corrosion resistance, then durability is improved, but manufacturing cost is significantly increased

Engineering Contradiction:

Improvecorrosion resistanceVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of using expensive corrosion-resistant materials like carbon nanotubes or diamond-like carbon, the patent uses a conventional electrode pair covered by a protective film. The electrode pair can be made of ordinary conductive materials, and the corrosion protection is achieved through the protective film rather than expensive materials, significantly reducing manufacturing cost.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If gold-plating is applied to the electrode pair to prevent corrosion, then durability is improved, but manufacturing cost is increased

Engineering Contradiction:

Improvecorrosion resistanceVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive gold-plating with a protective film coating method. The electrode pair is covered with an insulating protective film that can be applied through conventional coating processes, eliminating the need for expensive gold plating while maintaining corrosion protection functionality.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

4Reliability

If AC current is supplied to measure resistance through the insulating protective film, then durability is maintained, but measurement accuracy is affected by parasitic capacitance

Engineering Contradiction:

ImprovedurabilityVSAvoidresistance measurement accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The parasitic capacitance of the insulating protective film is measured and stored in advance. During resistance measurement, this stored parasitic capacitance value is used to compensate for the measurement error, providing feedback correction that restores measurement accuracy despite the presence of the insulating film.

Inventive Principle:

Principle #23Feedback

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 solution enhances the durability and accuracy of property determination in liquids while keeping manufacturing costs low, effectively addressing the corrosion and cost issues of previous technologies.

Implementation Method 1

a resistance measurement part that supplies AC current to the first electrode pair to measure the resistance value of a medium around the first electrode pair

Methodology Applied

Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

By covering the first electrode pair for measuring the resistance value of the medium with the insulating protective film, the corrosion of the first electrode pair can be prevented

Methodology Applied

Scientific EffectPhysical Containment: Physical Containment

Implementation Method 3

a storage part that holds the parasitic capacitance of the first electrode pair; a property determination part that, on the basis of the resistance value and the parasitic capacitance, determines a property of the medium

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS11035893B2Sensor device

Publication Date: 2021.06.15 NIPPON PILLAR PACKING CO LTD

AI summary

The present invention intends to provide a liquid sensor device that achieves both the improvement of durability and the improvement of property determination accuracy. The liquid sensor device includes: an electrode pair 22 that is formed on a sensor board 2 and covered by an insulating protective film 201; a resistance measurement part 302 that supplies AC current to the electrode pair 22 to measure the resistance value of oil 4; a parasitic capacitance storage part 304 that holds the parasitic capacitance Cs of the electrode pair 22; and a property determination part 313 that, on the basis of the resistance value R1 and the parasitic capacitance Cs, determines the deterioration of the oil 4.