Leak Detection Using CO2 Sensor and Color-Changing Foam

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Solution Overview

Problem

Existing leak detection methods, particularly those using smoke, struggle to accurately locate small leaks in sealed systems due to limitations in hole size detection, visibility issues in varying lighting conditions, and the presence of moving air, and are not effective for low and high-pressure systems.

Innovation Solution

A method utilizing pressurized CO2 gas and an electronic sensor to detect leaks, combined with a surfactant-containing foam that changes color in the presence of CO2 to indicate leak locations, allowing for quick and accurate detection of leaks as small as 0.001" in diameter in various conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If smoke is used for leak detection, then visibility of leak location is improved, but detection precision for small leaks deteriorates

Engineering Contradiction:
ImprovevisibilityVSAvoidleak detection precision
Core Design Contradiction:
Illumination intensityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical/visual smoke-based detection system with an electronic sensor-based detection system. The electronic sensor detects CO2 gas concentration to identify leak locations, eliminating the need for smoke generation while achieving both visibility and precision for small leaks (0.001" diameter).

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

Solution Approach 2:

The patent changes the detection parameter from visual observation of smoke to electronic measurement of CO2 gas concentration. This parameter change enables detection of much smaller leaks while maintaining visibility through electronic indicators, resolving the contradiction between visibility and detection precision.

Inventive Principle:
Principle #35Parameter changes

2Difficulty of detecting and measuring

If smoke generating machines are used, then leak detection capability is improved, but device complexity increases

Engineering Contradiction:
Improveleak detection capabilityVSAvoiddevice complexity
Core Design Contradiction:
Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The patent extracts the essential detection function from the complex smoke generating machine system. By using only an electronic sensor to detect CO2 gas, the system eliminates the smoke generation apparatus, fluid reservoirs, and complex control mechanisms while retaining leak detection capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces expensive, complex smoke generating machines with a simple, inexpensive electronic sensor system. The sensor-based approach uses readily available CO2 gas and simple electronic components, dramatically reducing device complexity and cost while maintaining detection effectiveness.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Adaptability or versatility

If smoke is used in moving air conditions, then leak detection is attempted, but measurement precision deteriorates

Engineering Contradiction:
Improveadaptability to moving airVSAvoidleak location precision
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent replaces smoke-based detection with electronic sensor-based detection of CO2 gas. Electronic sensors can accurately measure gas concentration regardless of air movement, eliminating the precision problems caused by smoke being dispersed by moving air while maintaining adaptability to various environmental conditions.

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

4Illumination intensity

If fluorescent dye is used with smoke, then leak visibility is improved, but loss of substance increases

Engineering Contradiction:
Improveleak visibilityVSAvoidchemical consumption
Core Design Contradiction:
Illumination intensityVSLoss of substance

Solution Approach 1:

The patent replaces the chemical-based fluorescent dye system with an electronic sensor detection system. The electronic sensor detects CO2 gas concentration without requiring any chemical substances, eliminating chemical consumption while maintaining leak visibility through electronic indicators and display devices.

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

Enables fast and precise leak detection in both low and high-pressure systems, effective in varying lighting and with moving air, and capable of identifying leaks down to 0.001" in diameter, without the need for smoke generating machines or chemicals.

Implementation Method 1

a surfactant-containing foam that changes color in the presence of CO2 to indicate leak locations

Methodology Applied
Scientific EffectColor change reaction:

Implementation Method 2

an electronic sensor that senses the presence of the pressurized gas which has escaped from such sealed system

Methodology Applied
Scientific EffectGas detection:

Implementation Method 3

This method uses pressurized gas that is put into a sealed system in order to find leakage

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP2951571B1Leak detection formula, analyzer and methods
Publication Date: 2019.01.09 AUTOMOTIVE TEST SOLUTIONS
  • EP2951571B1 patent drawingFigure 1
  • EP2951571B1 patent drawingFigure 2
  • EP2951571B1 patent drawingFigure 3A

AI summary

Detecting a leak from a site in a sealed system with a source of pressurized gas which is capable of passing through the site, a composition of matter which adheres to the surfaces of the system and which is capable of showing the presence of the gas escaping from the site. The method includes: injecting gas into the system to a pressure in excess of the surrounding pressure, and covering the external surface with the composition to identify the location of the site by the interaction of the escaping gas with the composition. The composition is foam that includes a surfactant which forms a least one bubble in the presence of escaping gas and an indicator which changes color in the presence of the escaping gas. The leak is an opening down to at least the size of a hole 0.001" in diameter. A gas detector may also be used.