Magnetoresistive Sensor Temperature Compensation

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Solution Overview

Problem

Existing magnetic field measurement technologies face challenges with large measurement errors due to temperature dependence and unknown magnetic field direction, particularly over wide temperature ranges and rapid temperature changes, and require difficult matching of magnetoresistive films.

Innovation Solution

A device comprising a magnetoresistive sensor with a polycrystalline thin film and a resistive temperature sensor, both connected in series with a dielectric heat-conductive intermediate layer, allowing for real-time temperature measurement to correct for temperature effects and eliminate directional sensitivity, using polycrystalline lanthanum-strontium-manganese oxide and platinum films respectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If magnetoresistive sensors are used to measure magnetic field, then magnetic field measurement capability is achieved, but measurement precision deteriorates due to temperature dependence and directional sensitivity

Engineering Contradiction:
Improvemagnetic field measurement accuracyVSAvoidtemperature dependence and directional sensitivity
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The device segments the measurement function into two independent sensors: a magnetoresistive sensor for magnetic field detection and a resistive temperature sensor for temperature detection. This segmentation allows each sensor to specialize in one measurement, eliminating the temperature dependence and directional sensitivity issues that affect single-sensor systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a dielectric heat-conductive intermediate layer as a mediator between the magnetoresistive and temperature sensors. This intermediate layer thermally couples the sensors to achieve consistent temperature measurement while maintaining electrical isolation, enabling accurate temperature compensation of the magnetoresistive sensor output.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If two magnetoresistive sensors are used to reduce temperature dependence, then temperature stability improves, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvetemperature stabilityVSAvoidsensor configuration complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

Instead of using two complex magnetoresistive sensors with different temperature dependencies, the patent copies only the temperature sensing function using a simple resistive temperature sensor. This copying approach maintains temperature stability while dramatically simplifying device structure and manufacturing, as the resistive sensor requires no magnetic field sensitivity calibration.

Inventive Principle:
Principle #26Copying

3Temperature

If magnetoresistive sensors are used for wide temperature range measurement, then measurement coverage expands, but measurement precision deteriorates due to rapid temperature changes

Engineering Contradiction:
Improveoperating temperature rangeVSAvoidmeasurement accuracy during rapid temperature changes
Core Design Contradiction:
TemperatureVSMeasurement precision

Solution Approach 1:

The patent implements feedback by continuously measuring temperature with the resistive temperature sensor and using this temperature information to compensate the magnetoresistive sensor output. This feedback mechanism enables accurate magnetic field measurement across wide temperature ranges and during rapid temperature changes, as the system actively adjusts for temperature effects in real-time.

Inventive Principle:
Principle #23Feedback

4Measurement precision

If magnetoresistive films are carefully matched for use in one sensor, then measurement accuracy improves, but manufacturing complexity and time increase

Engineering Contradiction:
Improvesensor measurement accuracyVSAvoidmanufacturing efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent copies the temperature sensing function using a simple resistive temperature sensor instead of requiring carefully matched magnetoresistive films. This eliminates the need for complex film matching procedures, significantly improving manufacturing efficiency while maintaining measurement accuracy through temperature compensation.

Inventive Principle:
Principle #26Copying

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

This solution simplifies manufacturing, expands the operating temperature range, and improves measurement accuracy, especially during rapid temperature changes, enabling precise scalar magnetic field measurements in compact devices.

Implementation Method 1

a thin polycrystalline material film (1) whose electrical resistance varies depending on the magnetic field and temperature

Methodology Applied
Scientific EffectMagnetoresistance: Magnetoresistance

Implementation Method 2

a temperature-sensitive metal thin film (6) which is insensitive to the magnetic field and to which connecting leads are attached for connecting a power source so that to form a series electrical circuit through said temperature sensitive resistive thin metal film

Methodology Applied
Scientific EffectResistive temperature sensing: Thermo-resistive Effect

Implementation Method 3

separated one from the other by a dielectric heat-conductive intermediate layer (10)

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3023804B1Magnetic induction measuring device and method
Publication Date: 2019.11.27 VALSTYBINIS MOKSLINIU TYRIMU INSTS FIZINIU & TECHNOLOGIJOS MOKSLU CENTRAS
  • EP3023804B1 patent drawingFigure 1a~1c
  • EP3023804B1 patent drawingFigure 2a~2b

AI summary

The invention relates to measuring instruments, used to measure a magnetic field. It can be used in measuring, controlling and monitoring systems where constant or variable scalar magnetic flux density (magnetic induction) measurements are taken. The device transforms the magnetic induction values into an electrical signal indicating the resistance change using a thin magnetoresistive manganite film sensor. In order to compensate the temperature errors, the device is provided with resistive temperature sensor comprising a thin temperature-sensitive metal film, which is insensitive to the magnetic field for determining the temperature in real time. The thin films of the two sensors are parallel to each other, face one another and separated by a thin layer of heat conductive dielectric thermally softened compound.