Magnetic Field Sensor Oxygen Measurement

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Solution Overview

Problem

Existing oxygen measurement devices are complex, prone to shocks, and not suitable for aggressive gases, with known technologies being difficult to assemble and unreliable for certain gas types.

Innovation Solution

A component using magnetic field sensors, specifically AMR or TMR sensors, to determine oxygen proportion in gases by measuring changes in magnetic field resistance, which is robust, simple to manufacture, and resistant to errors and vibrations, allowing for the measurement of aggressive gases without moving parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a magnetomechanical system with a rotating dumbbell sensor element is used to determine oxygen concentration, then oxygen measurement capability is achieved, but the device structure becomes extremely complicated and difficult to assemble

Engineering Contradiction:
Improveoxygen measurement capabilityVSAvoiddevice structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical magnetomechanical system (rotating dumbbell sensor element) with a magnetic field sensor that directly measures magnetic field changes. This substitution eliminates the complex mechanical rotating components while maintaining oxygen measurement capability, thereby resolving the contradiction between measurement precision and device complexity

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

Solution Approach 2:

The patent extracts and removes the unnecessary mechanical components (rotating dumbbell, optical detection system) from the measurement system, keeping only the essential magnetic field sensing function. This extraction simplifies the device structure while preserving the core measurement capability

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If a magnetomechanical system with moving parts is used for oxygen measurement, then measurement function is provided, but the device becomes prone to shocks and damage

Engineering Contradiction:
Improveoxygen measurement functionVSAvoidsusceptibility to shocks
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the mechanical system with moving parts (rotating dumbbell) with a stationary magnetic field sensor. This eliminates mechanical wear, friction, and susceptibility to shocks from vibrations and impacts, thereby improving reliability while maintaining the oxygen measurement function

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

Solution Approach 2:

The patent separates the sensing function from the mechanical structure, creating a standalone magnetic field sensor that can operate independently without mechanical support structures. This segmentation allows the sensor to be more robust and less susceptible to mechanical damage

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If a magnetomechanical system is used for oxygen measurement, then oxygen detection is enabled, but the device cannot be used for aggressive gases

Engineering Contradiction:
Improveoxygen detection capabilityVSAvoidsuitability for aggressive gases
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent replaces the mechanical sensor system with a magnetic field sensor that has no physical contact with the gas stream. This eliminates the problem of mechanical components being corroded or damaged by aggressive gases, thereby improving adaptability and versatility for measuring various gas types including aggressive ones

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

Solution Approach 2:

The patent uses the magnetic field as an intermediary between the sensor and the gas. The magnetic field sensor measures oxygen concentration through magnetic field interactions without direct physical contact with the gas, providing protection against corrosion and damage from aggressive gases while maintaining detection capability

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If traditional oxygen sensor designs are used, then measurement function is achieved, but manufacturing costs and assembly difficulty increase

Engineering Contradiction:
Improveoxygen measurement functionVSAvoidassembly difficulty
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces complex mechanical assemblies with a simple magnetic field sensor that can be mounted directly on the housing. This substitution dramatically reduces assembly steps and manufacturing complexity while maintaining the oxygen measurement function, making the device easier and more cost-effective to manufacture

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 provides a reliable, cost-effective, and miniaturized method for determining oxygen and paramagnetic gas proportions, offering improved robustness and sensitivity, enabling accurate measurements even in challenging gas environments.

Implementation Method 1

Gases are magnetized in a magnetic field. A measure of the magnetization is the magnetic susceptibility. Most gases have a negative susceptibility and therefore exhibit diamagnetic behavior... On the other hand, a few gases, in particular oxygen (O2), exhibit positive susceptibility and therefore paramagnetic behavior.

Methodology Applied
Scientific EffectMagnetic susceptibility: Magnetism

Implementation Method 2

Magnetic field sensors, also known as magnetoresistive sensors, are sensors whose electrical resistance changes depending on the change in the magnetic field in which the sensor is located.

Methodology Applied
Scientific EffectMagnetoresistance: Magnetoresistance

Implementation Method 3

The function of these sensors is based on either the anisotropic magnetoresistance effect, the tunneling magnetoresistance or the giant magnetoresistance effect.

Methodology Applied
Scientific EffectAnisotropic magnetoresistance effect: Magnetoresistance

Implementation Method 4

The function of these sensors is based on either the anisotropic magnetoresistance effect, the tunneling magnetoresistance or the giant magnetoresistance effect.

Methodology Applied
Scientific EffectTunneling magnetoresistance: Magnetoresistance

Implementation Method 5

The function of these sensors is based on either the anisotropic magnetoresistance effect, the tunneling magnetoresistance or the giant magnetoresistance effect.

Methodology Applied
Scientific EffectGiant magnetoresistance effect: Magnetoresistance

Data Source

PatentEP2320243B1Component for a device for determining the proportion of oxygen in a gas, device with such a component, use of a magnetic field sensor and method for determining the proportion of oxygen in a gas
Publication Date: 2011.12.14 M&C TECHGROUP GERMANY GMBH
  • EP2320243B1 patent drawingFigure 1
  • EP2320243B1 patent drawingFigure 2
  • EP2320243B1 patent drawingFigure 3

AI summary

The component (1) has magnetic field generation units i.e. permanent magnets (5), for generating a magnetic field. A gas flow unit (19) made of diamagnetic materials conducts gas through the generated magnetic field. A magnetic field sensor (27) e.g. giant magnetoresistance (GMR) magnetic sensor, is arranged in the magnetic field such that a change of the magnetic field caused by conducting of the gas through the magnetic field leads to a change of resistance of the sensor. The sensor is arranged at a distance from the gas flow unit, where the distance is not more than 1mm. An independent claim is also included for a method for determining the fraction of oxygen in a gas.