Sapphire Fiber Probe Window for High-Temperature Pressure Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical temperature sensors face issues with protective window damage due to decreased pressure resistance in high-temperature environments, such as those found in injection molding machines, leading to potential failure.
Innovation Solution
The optical temperature sensor employs a protective window made of sapphire with a-face surfaces on both sides, supported by a sleeve material with a lower thermal expansion coefficient, and a receiving section to maintain a stable air layer and distribute pressure, preventing damage and ensuring high pressure resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective window is provided to protect the optical fiber, then the optical fiber is protected from damage, but the pressure resistance of the protective window decreases in high-temperature environments
Solution Approach 1:
The patent changes the crystal orientation parameter of the sapphire protective window by specifying that the first surface is an a-face and the second surface is a c-face. This parameter change in crystal orientation maintains the compressive stress state in high-temperature environments, preventing the protective window from becoming brittle and maintaining its pressure resistance while still protecting the optical fiber.
2Temperature
If the protective window is made of sapphire, then high temperature resistance is achieved, but pressure resistance decreases at high temperatures
Solution Approach 1:
The patent specifies the crystal orientation parameters of the sapphire protective window (a-face and c-face surfaces) to maintain the compressive stress state at high temperatures. This parameter specification ensures that sapphire retains its pressure resistance despite temperature increases, resolving the contradiction between temperature resistance and pressure resistance.
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 maintains high pressure resistance of the protective window in high-temperature environments, preventing damage and ensuring accurate temperature measurements by minimizing optical interference and resin intrusion.
Implementation Method 1
the maximum compressive stress of the protective window in a high-temperature environment is unlikely to decrease compared to that in a normal temperature environment
Data Source
AI summary
An optical temperature sensor includes a cylindrical fiber probe into which an optical fiber is threaded, and a protective window that is formed of sapphire and positioned on the distal end side of the fiber probe. The surface of the protective window opposite to the optical fiber in the axial direction of the fiber probe is formed as a first surface, the surface of the protective window facing the optical fiber is formed as a second surface, and the first surface is an a-face of the sapphire.