LED Flash Thermal Diffusivity Instrument with Multi-Sample Holder
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Solution Overview
Problem
Existing methods for measuring thermal diffusivity are limited by the need for complex corrections due to heat losses and finite pulse widths, which require post-test data manipulation and do not allow for real-time variation of test parameters.
Innovation Solution
A device and method using a high-intensity short-duration flash of light from an LED, laser diode, or LED array to measure thermal diffusivity in disc-shaped materials, with a multi-sample holder and a thermally controlled environment, allowing for real-time analysis and variation of test parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional flash diffusivity apparatus using Xenon light source or pulse laser is used, then thermal diffusivity can be measured, but complex corrections are required due to heat losses and finite pulse widths
Solution Approach 1:
The patent replaces the traditional Xenon flash lamp or pulse laser system with an LED-based illumination system. This substitution simplifies the device by eliminating the need for complex optical components and high-voltage power supplies while maintaining the flash diffusivity measurement capability. The LED system inherently provides shorter effective pulse widths and reduced heat losses, thereby reducing the complexity of post-test data corrections.
Solution Approach 2:
The patent changes the illumination source parameters from high-intensity short-duration laser or Xenon flash to high-intensity LED flash. This parameter change in the light source characteristics (duration, intensity profile, spectral content) fundamentally alters the heat transfer dynamics in the sample, reducing radiative and conductive heat losses during the measurement process. Consequently, the corrections required for heat losses and finite pulse widths become less complex.
2Measurement precision
If post-test data manipulation is used for corrections, then measurement accuracy can be improved, but real-time variation of test parameters is not allowed
Solution Approach 1:
The patent implements preliminary action by designing the LED-based flash system to inherently minimize heat losses and optimize pulse characteristics before the measurement begins. The LED system's natural emission profile and shorter effective pulse duration pre-condition the experiment to require minimal corrections, enabling both accurate measurements and faster testing by reducing post-test data manipulation requirements.
Solution Approach 2:
The LED-based system provides self-service by automatically optimizing the illumination parameters for reduced heat losses without requiring complex external correction mechanisms. The system's inherent characteristics (shorter pulse width, controlled intensity profile) self-correct many of the measurement errors that would otherwise require elaborate post-processing, thereby improving both accuracy and productivity simultaneously.
3Productivity
If high intensity short duration flash is used, then measurement speed is improved, but heat losses and finite pulse width effects increase
Solution Approach 1:
The patent replaces the traditional high-intensity laser or Xenon flash system with an LED-based system that can achieve comparable or superior intensity with shorter effective pulse durations. This substitution maintains measurement speed while reducing the harmful effects of finite pulse width and heat losses, as the LED system's emission characteristics naturally minimize these effects compared to traditional high-intensity sources.
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 enables accurate and efficient measurement of thermal diffusivity with reduced errors, allowing for real-time data analysis and optimization of test parameters, thereby improving the precision and speed of thermal diffusivity testing.
Implementation Method 1
at least one light pulse from the LED light source impinges on one face of an opaque solid material sample of uniform thickness, L, producing a time dependent temperature evolution
Implementation Method 2
describes the rate with which heat spreads through a material, from a hotter to a colder region
Data Source
Figure 1~4
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AI summary
An instrument (1000) for determining thermal diffusivity of disc shaped opaque solid or quasi solid materials using a high intensity short duration flash of light from a single LED, a planar LED array, or laser diode source (504/400) is disclosed. This instrument (1000) comprises an axially and radially indexed cylindrical sample holder (501) able to accommodate a plurality of test samples (1) and sequentially bring them into a designated testing position to expose one face (A) of each sample (1) to the flash of light while the obverse face (B) of the sample (1) is observed by a temperature measuring device (505), for the purpose of recording the attendant thermal excursion. An improved calculating method, based on empirical data observed during each test, is used for calculating thermal diffusivity.