Contactless Temperature Sensor for Moving Copper Wires

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Solution Overview

Problem

Contactless temperature measurement of copper wires in movement is challenging due to copper's low infrared emissivity and small diameter, which results in limited energy flow and distortion from transversal vibrations, making existing pyrometric and convective heat exchange systems complex, costly, and prone to breakdowns.

Innovation Solution

A contactless temperature sensor using an insulated cavity with a highly diffusive sensitive element, where the copper wire transfers heat through convective phenomena, allowing passive thermal equilibrium and measurement with a calibrated pyrometer, eliminating the need for active regulation and control mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If pyrometric measurement is used for copper wires, then contactless temperature measurement is achieved, but measurement precision deteriorates due to low infrared emissivity of copper

Engineering Contradiction:
Improvecontactless measurementVSAvoidtemperature measurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary element (the cavity with high-emissivity coating) between the copper wire and the pyrometer. The copper wire transfers heat to the cavity walls through convection and radiation, and the cavity walls, having high infrared emissivity, radiate this heat towards the pyrometer, enabling accurate contactless measurement

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the emissivity parameter by using a cavity with high-emissivity coating (ε > 0.9) instead of measuring the copper wire's low-emissivity surface directly. This parameter transformation allows the pyrometer to receive sufficient infrared radiation for accurate temperature measurement

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If high magnification optics are used to focus on small wire diameter, then measurement precision improves, but device complexity increases and reliability decreases due to vibration sensitivity

Engineering Contradiction:
Improvemeasurement spot accuracyVSAvoidmeasurement stability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The cavity acts as an intermediary that decouples the measurement from the wire's physical position. The copper wire transfers heat to the cavity walls, and the pyrometer measures radiation from the cavity walls rather than directly from the moving wire, eliminating vibration-induced focal distortion

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent transitions from direct optical measurement in space to thermal equilibrium measurement in time. Instead of focusing on the wire's position in space (which is affected by vibrations), the system measures the thermal energy transferred to the cavity, which integrates over time and is insensitive to positional variations

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If active regulation and control mechanisms are implemented, then measurement precision improves, but device complexity and cost increase

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidsystem structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses passive thermal equilibrium without active regulation. The cavity naturally reaches thermal equilibrium with the copper wire through convective and radiative heat transfer, and the pyrometer passively measures the resulting temperature without requiring active control mechanisms

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical control systems with a passive thermal field-based measurement system. Instead of using active regulation mechanisms to maintain measurement conditions, the system relies on natural thermal equilibrium and passive radiation detection

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 sensor provides a simple, economical, and reliable contactless temperature measurement for copper wires in movement, with reduced breakdown risks and the ability to adapt measurement bandwidth, while being resistant to chemical and corrosive environments.

Implementation Method 1

a drawn copper wire (10) moves inside with a uniform velocity v... the copper wire transfers heat through convective phenomena

Methodology Applied
Scientific EffectConvective heat exchange: Convection

Implementation Method 2

The emission spectrum of a generic grey body obeys Planck's law... the temperature of a body can be transduced by measuring the infrared irradiation spectrum

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Data Source

PatentEP3249369B1Contactless temperature sensor for copper wires in movement
Publication Date: 2019.10.09 ELAV SRL
  • EP3249369B1 patent drawingFigure 1~2
  • EP3249369B1 patent drawingFigure 3~4
  • EP3249369B1 patent drawing

AI summary

A contactless temperature sensor for copper wires in movement, comprising a body of the sensor (12) which provides an insulated sealed cavity (19) wherein an insulated cavity (21,22) is provided inside the sealed cavity, having an axial development and with a sensitive element in the centre made of a material having a high thermal diffusion (11), a pyrometer (16) being positioned in the sensor body (12), which extends inside the sealed cavity (19) and faces the sensitive element with a high thermal diffusion (11).