Aircraft Temperature Sensor with Optical Fiber and Thermistor
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Solution Overview
Problem
Current aircraft temperature detection systems face limitations in accurately monitoring temperature anomalies, particularly in detecting lower temperature thresholds and providing continuous monitoring while maintaining reliability at high temperature events.
Innovation Solution
A temperature sensor design incorporating a central conductor, thermistor, and optical fiber within a sheath, where the optical fiber forms a helix with a constant tangent angle, and the thermistor defines a trough to retain the optical fiber, allowing for accurate temperature measurement and continuous monitoring with the ability to survive high temperature events.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single temperature sensor type is used, then the device complexity is reduced, but the measurement precision across different temperature ranges deteriorates
Solution Approach 1:
The patent combines three different temperature sensing mechanisms (conductor resistance change, thermistor resistance change, and optical fiber Bragg grating reflection shift) into a single integrated sensor assembly. All three sensors are disposed within the same sheath and measure temperature at the same location, allowing the system to achieve high measurement precision across a wide temperature range while maintaining relatively simple device structure through functional integration
2Reliability
If conventional temperature sensors are used, then the device complexity is low, but the reliability during high temperature events deteriorates
Solution Approach 1:
The optical fiber acts as an intermediary temperature sensing mechanism that does not require electrical power or signal transmission, making it inherently more reliable in high-temperature environments where electrical components may fail. The optical fiber Bragg grating provides temperature measurement through optical reflection characteristics that are less susceptible to thermal degradation compared to electrical sensors
Solution Approach 2:
The sensor assembly is filled with inert gas (nitrogen or helium) to create a protective atmosphere that prevents oxidation and thermal degradation of the internal components during high-temperature events, thereby enhancing reliability without significantly increasing device complexity
3Measurement precision
If continuous monitoring is implemented, then the measurement precision over time is improved, but the use of energy increases
Solution Approach 1:
The optical fiber-based temperature sensing replaces traditional electrical resistance measurement systems. Optical fibers can be continuously monitored with minimal energy consumption because they passively reflect light based on temperature-induced Bragg wavelength shifts, eliminating the need for continuous electrical power to maintain the sensing function
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 sensor effectively detects temperature fluctuations across a wide range, including lower thresholds, and continuously monitors temperatures, enabling precise alerts and operational responses, while the optical fiber's sacrificial nature during high events ensures system reliability.
Implementation Method 1
the optical fiber comprises a Bragg grating that reflects a spectrum of light that shifts in response to temperature
Implementation Method 2
The temperature sensor comprises a thermistor disposed within the sheath and surrounding the central conductor, the thermistor having thermistor material defining a thermistor temperature coefficient
Implementation Method 3
having a conductor material defining a conductor temperature coefficient having a conductor coefficient magnitude
Data Source
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AI summary
Disclosed is a sensor for detecting temperature of an aircraft. The sensor comprises a temperature sensor elongated with respect to an axis. The temperature sensor comprises a sheath elongated with respect to the axis. The temperature sensor comprises a central conductor disposed within the sheath and elongated with respect to the axis having a conductor material defining a conductor temperature coefficient having a conductor coefficient magnitude. The temperature sensor comprises an optical fiber disposed within the sheath. The temperature sensor comprises a thermistor disposed within the sheath and surrounding the central conductor, the thermistor having thermistor material defining a thermistor temperature coefficient defining a thermistor coefficient magnitude greater than the conductor coefficient magnitude.