Surface Temperature Sensor Cavity Layout to Limit Convective Heat Drain
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing measurement methods for surface temperature using photonic and optomechanical thermometry suffer from significant uncertainty due to temperature gradients, fiber-to-chip coupling, and temperature drops at the contact interface, which are not adequately addressed by conventional active compensation methods.
Innovation Solution
A device with a geometrically defined air passage in its housing, guiding air flow to create a stable atmosphere around the sensing element, either stagnant or vorticose, to minimize temperature gradients and reduce convective heat drains, using a cavity design that separates the air flow from direct contact with the sensing element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional active compensation methods are used to address temperature gradients and contact interface issues, then measurement uncertainty is reduced to some extent, but the device complexity and manufacturing difficulty increase significantly
Solution Approach 1:
The patent extracts and removes the air passage structure from the housing, creating a geometrically defined flow path that guides air away from the sensing element. This eliminates the need for complex active compensation mechanisms while maintaining measurement accuracy by preventing convective heat drain at the contact interface.
Solution Approach 2:
The patent introduces air as an intermediary substance that flows through the geometrically defined passage to compensate for temperature gradients. The air flow acts as a thermal mediator that balances temperature distribution without requiring complex active control systems.
2Measurement precision
If air flow is directed through the cavity to compensate temperature gradients, then measurement accuracy improves, but temperature drops at the contact interface occur due to convective heat drain
Solution Approach 1:
The cavity is segmented into distinct regions: a first portion in contact with the measured surface for air flow compensation of temperature gradients, and a second portion in contact with the sensing element that remains outside the air flow path. This segmentation allows differential treatment of thermal management for different components.
Solution Approach 2:
Different regions of the cavity are assigned different thermal characteristics. The first portion experiences air flow for gradient compensation, while the second portion near the sensing element is protected from direct air flow to prevent convective heat drain, ensuring local thermal quality optimization.
3Temperature
If the sensing element is placed in direct contact with the contact surface for thermal conduction, then thermal equilibrium is achieved, but temperature drops occur due to convective heat drain from air flow
Solution Approach 1:
The cavity is divided into a first portion for air flow compensation and a second portion for sensing element placement that is excluded from the air flow path, preventing direct convective interaction between the air flow and sensing element.
Solution Approach 2:
The substrate acts as an intermediary thermal conduction path between the contact surface and the sensing element, ensuring thermal equilibrium through solid conduction while the air flow mediates temperature gradient compensation in the surrounding environment without directly cooling the sensing element.
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 significantly reduces measurement uncertainty by up to 92%, improving the accuracy and performance of surface temperature measurements, particularly in photonic contact thermometry using silicon ring resonators and tuneable laser-based spectroscopy.
Implementation Method 1
a sensing element on the substrate such that the sensing element is in thermal contact with the contact surface by thermal conduction through the substrate
Implementation Method 2
The cavity defines an air flow path from the air inlet through the first portion to the air outlet such that the second portion of the cavity remains outside the air flow path
Data Source
AI summary
According to an example aspect of the present invention, there is provided a device for measuring surface temperature of an object. The device comprises a contact surface to be placed against a surface of the object. The device further comprises a chip having a substrate and a sensing element on the substrate such that the sensing element is in thermal contact with the contact surface by thermal conduction through the substrate. A housing is attached to the chip and has an air inlet and an air outlet. A cavity is provided inside the housing between the air inlet and the air outlet, the cavity comprising a first portion in contact with the surface of the object and a second portion in contact with the sensing element. The cavity defines an air flow path from the air inlet through the first portion to the air outlet such that the second portion of the cavity remains outside the air flow path.