Fluid Leak Detection Using Permittivity Rate Thresholds

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Solution Overview

Problem

Existing fluid leak detection methods, such as float switches and electrical conduction techniques, are prone to false alarms and require excessive water volume for activation, and often fail to detect leaks accurately due to sensitivity issues and contact corrosion.

Innovation Solution

A fluid leak detection device using a leak sensor to measure permittivity changes, with a microcontroller tracking the rate of change over time, generates an alarm when permittivity exceeds predetermined thresholds, minimizing false alarms by defining a specific air gap volume for water accumulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If float switches or electrical conduction techniques are used for leak detection, then the device can detect fluid leaks, but it requires excessive water volume for activation and generates false alarms

Engineering Contradiction:

Improveleak detection accuracyVSAvoidwater volume required for activation

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent replaces mechanical float switches and electrical conduction techniques with a permittivity-based detection system. The sensor measures changes in electrical permittivity of the air gap as water accumulates, eliminating the need for mechanical contact or excessive water volume to trigger an alarm.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes changes in permittivity as a detection parameter. As water accumulates in the air gap, the permittivity of the medium between sensor plates changes, providing a continuous measurement that triggers an alarm at a predetermined threshold, thereby reducing false alarms and eliminating the need for excessive water volume.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If existing leak detection methods are used, then fluid leaks can be detected, but false alarms occur due to sensitivity issues and contact corrosion

Engineering Contradiction:

Improvefalse alarm rateVSAvoidsensitivity to fluid presence

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent introduces an air gap as an intermediary medium between the sensor and the fluid. This air gap allows the sensor to detect water accumulation through permittivity changes without direct contact, thereby preventing contact corrosion and reducing false alarms while maintaining sensitivity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct contact-based detection methods with a non-contact permittivity measurement system. By measuring electrical permittivity changes in the air gap, the system achieves reliable detection without the sensitivity issues and contact corrosion associated with traditional methods.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If the sensor is placed in direct contact with the leakage surface, then water accumulation can be detected, but contact corrosion occurs and false alarms increase

Engineering Contradiction:

Improvedetection reliabilityVSAvoidcontact corrosion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an air gap as an intermediary between the sensor and the leakage surface. This air gap prevents direct contact between the sensor and water, eliminating contact corrosion while still allowing detection of water accumulation through permittivity changes in the air gap.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct contact-based sensing with a non-contact permittivity measurement system. The sensor measures electrical properties of the air gap rather than contacting the water directly, thereby preventing corrosion and reducing false alarms while maintaining detection reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 effectively detects fluid leaks with reduced false alarms by accurately measuring permittivity changes and rate of change, ensuring that only significant water accumulation triggers an alarm, thus improving leak detection reliability.

Implementation Method 1

a leak sensor configured to sense permittivity of an electric field in proximity of a fluid leakage

Methodology Applied

Scientific EffectPermittivity: Dielectric Permittivity

Data Source

PatentUS8508373B2Fluid leak detection and alarm

Publication Date: 2013.08.13 RICE TECHNOLOGY LLC

AI summary

A method and a device are disclosed for reliably detecting fluid leaks while minimizing false alarms. A leak sensor in proximity of a flat leakage surface, such as a floor area, is used to sense a permittivity of a media, such as water, coming in contact with the leak sensor. Leak is indicated if the sensed permittivity exceeds a permittivity threshold within a predefined time period. The predefined time period indicates a rate threshold that if exceeded indicates relatively fast accumulation of fluid in an air gap between the leak sensor and the leakage surface, precluding or reducing the possibility of false alarm due to gradual increase in environmental humidity or moisture. The air gap defines a fluid volume that is substantially filled before leak is detected.