Phase Transition Filler for Temperature Monitoring in Sensor Heads

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing field devices lack an efficient method to detect exposure to excessively high operating temperatures, which can lead to defects or failure, and current solutions often require complex designs or separate sensor units.

Innovation Solution

A device utilizing a filler material with predeterminable phase transition temperatures that remains in the solid phase, allowing for detection of phase states to indicate temperature exceedance, with a detection unit to monitor and output messages on phase changes, enabling easy detection of high temperature exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a temperature-exceeding element with piezoelectric material is used to detect high temperature, then temperature monitoring capability is improved, but the device complexity increases and requires special design for polarization interrogation

Engineering Contradiction:
Improvetemperature monitoring capabilityVSAvoiddesign complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a filler material that undergoes a phase transition at a predeterminable temperature corresponding to the maximum operating temperature of the sensor unit. This phase transition provides a clear, detectable signal that the maximum temperature has been reached, enabling reliable temperature monitoring without complex piezoelectric elements or polarization interrogation systems.

Inventive Principle:
Principle #36Phase transitions

2Reliability

If impedance measuring unit is used to detect sensor defects, then defect detection capability is improved, but the ability to detect temperature exposure before damage occurs is lost

Engineering Contradiction:
Improvedefect detection capabilityVSAvoidtemperature exposure detection
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent places a temperature-sensitive filler material in thermal contact with the sensor unit before operation. This filler material undergoes a phase transition at the maximum operating temperature, providing advance warning of temperature exposure before actual damage occurs to the sensor unit or electrical connections. This preliminary detection capability allows preventive action before defects develop.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If separate temperature switch units are used to detect high temperature, then temperature detection capability is improved, but the device complexity and integration difficulty increase

Engineering Contradiction:
Improvetemperature detection capabilityVSAvoidintegration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates the temperature detection function directly into the existing housing structure by incorporating a filler material that serves as both structural filler and temperature-sensitive indicator. This merging of functions eliminates the need for separate temperature switch units and their associated mounting, wiring, and interrogation systems, significantly reducing device complexity while maintaining reliable temperature detection capability.

Inventive Principle:
Principle #5Merging (Combining)

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 reliable detection of maximum operating temperature exceedance without falsifying temperature measurements, providing structural advantages and simplifying the design, allowing for passive detection of thermal stress and aiding in analyzing device defects.

Implementation Method 1

a filler material (10) for which a phase transition occurs at a predeterminable phase transition temperature TP, for which phase transition the material remains in the solid phase

Methodology Applied
Scientific EffectPhase transition: Phase Change

Implementation Method 2

the device (1), in particular an electronics of the device (1), or the detection unit (11) can be designed to output a message regarding the phase state of the filling material or regarding a change in the phase state of the filling material

Methodology Applied
Scientific EffectPhase state detection:

Data Source

PatentEP3847431B1Measuring insert with state monitoring
Publication Date: 2024.07.03 ENDRESS & HAUSER GMBH & CO KG
  • EP3847431B1 patent drawingFigure 1
  • EP3847431B1 patent drawingFigure 2~3
  • EP3847431B1 patent drawingFigure 4a~4c

AI summary

The invention relates to a device (1) for determining and/or monitoring a process variable of a medium (5), comprising at least one sensor element (7) arranged in a sensor head (3), for determining and/or monitoring the process variable, wherein at least one sub-region of an inner space (V) of the sensor head (3), in which the sensor element (7) is arranged, is at least partially, particularly completely, filled with a filler (6). According to the invention, the filler (6) comprises at least one filler material (10) for which a phase transition occurs at at least one predefinable phase transition temperature (TP), the material remaining in the solid phase for said phase transition, wherein the filling material (10) is in a first phase state (P2) if a temperature (T) of the filling material (10) is lower than the phase transition temperature (TP), and wherein the filling material (10) is in a second phase state (P2) if the temperature (T) of the filling material (10) is higher than the phase transition temperature (TP).