Discontinuous liquid level sensor based on optical fiber bragg grating technology

Abstract

Provided is a discontinuous liquid level sensor based on the optical fiber bragg grating technology. The discontinuous liquid level sensor comprises a broadband light source, a 3dB optical fiber coupler, an FBG sensing array, a wavelength demodulation module and a micro-control unit. Light output by the broadband light source passes through a temperature reference optical grating and a stress sensing optical grating which are stuck to a cantilever beam structure in the FBG sensing array in sequence through the 3dB optical fiber coupler, and the packaging material of a sensing probe, the floater material and the optical grating sticking material all adopt carbon fiber; the liquid level change can change the acting force of a magnet on a floater to sheet iron on a carbon fiber plate, the carbon fiber plate is made to be deformed, the reflection wavelength of the sensing optical grating is changed, reflected light is input into the wavelength demodulation module through the 3dB optical fiber coupler, and demodulation of the reflection wavelength is completed; a signal is transmitted to the micro-control unit with a temperature-stress compensation algorithm for data processing. The discontinuous liquid level sensor is simple and reliable in structure, high in detection precision and sensitivity and capable of being applied to severe environments such as high temperature and high corrosion and achieving discontinuous detection of liquid levels of different heights.

Description

technical field [0001] The invention relates to a discontinuous liquid level monitoring sensor, in particular to a liquid level sensor which is based on fiber Bragg grating technology and a non-contact cantilever beam mechanical structure and can be applied in harsh environments. Background technique [0002] Liquid level monitoring is one of the main tasks of process control. Liquid level sensor is a device for detecting liquid height. It has important and extensive applications in daily life and modern production. With the intelligentization and unification of the control system, the objects of liquid level measurement are becoming more and more extensive, and the liquid level sensor is required to have higher measurement accuracy, better reliability, stronger practicability, and more suitable for special measurement environments. Especially when the measured medium is viscous, conductive, or the liquid level fluctuates or there are bubbles, or it is necessary to consider ...

AI Technical Summary

Problems solved by technology

Because most of this technology uses the end of the optical fiber or prism as the sensing probe to contact the liquid, the exposed sensing probe may be affected by dynamic disturbances from floating objects, vibrations, and filling. bio-adhesion or chemical pollution, the sensor needs routine maintenance, and the workload is greatly increased

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