Bragg Grating Optical Fiber Sensor for EMI/RFI-Free Field Measurement
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Solution Overview
Problem
Traditional magnetic field sensors using current-carrying conductors are prone to electromagnetic and radio frequency interference, leading to inaccurate measurements.
Innovation Solution
An optical fiber sensor is designed with a magnetic component connected to a Bragg grating on an optical fiber, allowing the magnetic component to move under magnetic force, causing the grating to bend and deform, and the wavelength of reflected light waves to change, which is analyzed to calculate magnetic field intensity without electrical current passing through the optical fiber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current-carrying conductors are used as sensing elements in traditional magnetic field sensors, then the measurement function is achieved, but electromagnetic interference and radio frequency interference occur, reducing measurement accuracy
Solution Approach 1:
The patent replaces the electrical sensing system (current-carrying conductors) with an optical sensing system (optical fiber with Bragg grating). The optical fiber sensor uses light wavelength changes to detect magnetic field-induced mechanical deformation, eliminating electrical current flow through the sensing element and thus avoiding electromagnetic and radio frequency interference while maintaining measurement functionality.
2Object-affected harmful factors
If optical fiber with Bragg grating is used instead of current-carrying conductors, then electromagnetic and radio frequency interference is avoided, but the device structure becomes more complex
Solution Approach 1:
The patent merges the magnetic sensing function with the optical fiber structure by directly attaching the magnetic component to the optical fiber at the Bragg grating position. This integration eliminates the need for separate electrical conductors and complex electrical connection systems, reducing overall device complexity despite using optical technology.
Solution Approach 2:
The optical fiber serves multiple functions: it acts as both the structural support and the sensing element. The Bragg grating written on the optical fiber provides both the mechanical coupling point for the magnetic component and the optical sensing mechanism, reducing the need for additional separate components.
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 optical fiber sensor avoids electromagnetic and radio frequency interference, improving measurement accuracy and reducing production costs by eliminating the need for current-carrying conductors, while maintaining electrical isolation and wide environmental applicability.
Implementation Method 1
the magnetic component is capable of positional offset under an action of a magnetic force to cause the Bragg grating at the preset position to undergo bending and deformation
Implementation Method 2
a Bragg grating is formed at the preset position
Data Source
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AI summary
The present application relates to the technical field of optical fiber sensing, and provides an optical fiber sensor and a magnetic field intensity measurement device. The optical fiber sensor includes: at least one optical fiber and a magnetic component; the at least one optical fiber is extended and arranged along a preset direction, a preset position is arranged on an extension length of the optical fiber, and a Bragg grating is formed at the preset position; and the magnetic component is connected to the preset position of the optical fiber, the magnetic component is capable of positional offset under an action of a magnetic force to cause the Bragg grating at the preset position to undergo bending and deformation perpendicular to the preset direction. The magnetic field intensity measurement device includes the above optical fiber sensor. The present application aims to solve the technical problem in the existing technology that the current-carrying conductors are prone to electromagnetic and radio frequency interference, resulting in inaccurate measurement of magnetic field intensity.