Fiber Grating Hydrogen Sensor With Three-Port Interferometer
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Solution Overview
Problem
Existing hydrogen detection methods using palladium-based optical detectors are slow and inefficient, making them unsuitable for rapid and accurate detection of hydrogen due to its explosive nature.
Innovation Solution
An optical sensor system utilizing a fiber grating sensor with a mechanically responsive surface coating and a multi-port interferometer, particularly a three-port interferometer, to enhance sensitivity and accuracy by reducing noise levels and enabling faster detection of subtle changes in material properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a palladium layer is applied to an optical detector to detect hydrogen, then detection accuracy is improved, but response time deteriorates (measurements become slow)
Solution Approach 1:
The patent changes the physical state and structure of the detection system by transitioning from conventional optical detectors with palladium layers to fiber optic-based sensors. This parameter change enables both high detection accuracy and fast response time by utilizing the unique properties of fiber optics and palladium's hydrogen absorption characteristics in a integrated sensor design.
Solution Approach 2:
The patent employs composite material structures by combining fiber optic technology with palladium-based detection layers. The composite structure integrates the optical transmission capabilities of fiber optics with the hydrogen-sensitive properties of palladium, achieving both accuracy and speed requirements for hydrogen detection.
2Measurement precision
If conventional optical detectors are used with palladium layers, then detection accuracy is achieved, but detection efficiency deteriorates (measurements are slow and inefficient)
Solution Approach 1:
The patent replaces conventional mechanical/optical detector systems with a fiber optic-based sensing system. This substitution eliminates the limitations of traditional detectors by using fiber optic technology that provides both high measurement precision and rapid response, thereby improving overall detection efficiency and productivity.
Solution Approach 2:
The invention changes key system parameters by adopting fiber optic technology with specific numerical aperture values (0.1 to 0.5) and optimized palladium layer configurations. These parameter changes enable the system to achieve both accurate measurements and high detection efficiency, resolving the contradiction between precision and productivity.
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 system achieves significantly improved accuracy and response time in detecting hydrogen by reducing noise levels by a factor of 100, allowing for early detection of subtle changes in the presence of hydrogen, thus enhancing safety in hydrogen environments.
Implementation Method 1
a fiber section including an internal structural periodicity such as to reflect, upon receiving an optical interrogation signal in use, optical radiation at a reflection wavelength that is dependent on the internal structural periodicity
Implementation Method 2
an interferometer, wherein the interferometer is configured for splitting the optical output signal into at least a first signal fraction and a second signal fraction
Implementation Method 3
the surface coating being of a material that is mechanically responsive to the presence of the chemical substance ambient thereto
Implementation Method 4
Palladium is known to absorb hydrogen very well, forming palladium hydride which is an alloy consisting of two crystalline phases, α and β
Data Source
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AI summary
The invention is directed at an optical sensor system for detecting a chemical substance. A fiber grating sensor responsive to the substance comprises a grating to reflect or transmit optical radiation at a reflection/transmission wavelength. The sensor comprises a radiation source, an interferometer, and an optical conveyance structure configured for conveying the interrogation signal to the fiber grating sensor. The interferometer provides a combined interference signal to at least three output ports of a coupler. Each of the at least three output ports thereby provides a respective output signal, wherein a fixed mutual phase difference is present between each two output signals. The fiber grating sensor comprises a surface coating forming an exterior casing, the surface coating being of a material that is mechanically responsive to the presence of the chemical substance ambient thereto.