Transient Plane Source Sensor Thermal Property Measurement
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Solution Overview
Problem
Existing transient plane source systems are inadequate for measuring thermal properties of small, conductive, and anisotropic solid materials, as they require volumetric heat capacity input and truncate data, leading to inaccurate results.
Innovation Solution
A method using a transient plane source sensor with non-linear fitting techniques to determine thermal properties of small and/or conductive sample materials, eliminating the need for volumetric heat capacity input and accounting for anisotropic properties by applying a temperature equation that includes thermal transport properties, time, and power supplied, with the sensor placed in contact with solid cylinder slabs to provide temperature responses at radial boundaries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing transient plane source systems are used for small, conductive, and anisotropic samples, then measurement can be performed, but measurement precision deteriorates due to required volumetric heat capacity input and data truncation
Solution Approach 1:
The patent changes the mathematical model parameters by using a non-linear fitting technique that incorporates the complete temperature equation with thermal conductivity, thermal diffusivity, and volumetric heat capacity as fit parameters. This allows the system to adapt to small, conductive, and anisotropic samples without requiring pre-input of volumetric heat capacity, thereby improving measurement precision while maintaining versatility.
Solution Approach 2:
The patent implements a feedback mechanism through iterative non-linear fitting, where the measured temperature data is continuously compared with the modeled temperature data, and the fit parameters are adjusted until convergence is achieved. This feedback loop enables accurate determination of thermal properties for challenging sample types without data truncation.
2Ease of operation
If data is truncated to handle small samples, then measurement can be performed, but measurement precision deteriorates due to omission of boundary thermal effects
Solution Approach 1:
The patent transitions from a one-dimensional heat conduction model (which requires data truncation) to a three-dimensional heat conduction model that accounts for radial, axial, and volumetric heat capacity effects. This dimensional expansion allows the complete temperature equation to be used for small samples without truncating data, thereby maintaining both ease of operation and measurement precision.
3Adaptability or versatility
If volumetric heat capacity is input to handle small samples, then measurement can be performed, but device complexity increases due to additional input requirements
Solution Approach 1:
The patent enables the system to self-determine volumetric heat capacity as a fit parameter rather than requiring it as external input. The non-linear fitting technique automatically calculates volumetric heat capacity from the temperature data and the other thermal properties, making the system self-sufficient and eliminating the need for additional input parameters while maintaining the capability to measure small samples.
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 approach allows for accurate measurement of thermal properties without requiring volumetric heat capacity input, effectively handling both isotropic and anisotropic materials by providing temperature responses at the boundaries, thereby improving measurement accuracy and reliability.
Implementation Method 1
electricity is passed through the sensor to heat up the surrounding sample of material. The sensor acts as both a heating and a heat-sensing item.
Implementation Method 2
the resistance of the sensor is related to the temperature of the surrounding sample material. Accordingly, a time-dependent temperature increase of the sample material can be recorded
Data Source
AI summary
Systems and methods are disclosed for determining a thermal property of a small and/or conductive sample material. Measurement data of the sample material is obtained using a transient plane source sensor placed in contact with at least one solid cylinder slab of the sample material, wherein each of the at least one solid cylinder slab of the sample material has a slab radius that is larger than a radius of the sensor and less than twice as large as the radius of the sensor. The power supplied to the transient plane source sensor over the measurement period is sufficient to provide a temperature response in at least a radial boundary of each of the at least one solid cylinder slab. A non-linear fitting technique is applied to determine a modeled thermal property of the sample material.