All-fiber non-invasive ultrasonic liquid level measurement system and method

Abstract

The application discloses a kind of all-optical fiber non-invasive ultrasonic liquid level measurement system, it includes fiber-optic photoacoustic transducer array to convert light pulse energy into ultrasonic wave, to non-invasive in the container wall of liquid bearing liquid excitation ultrasonic vibration;Fiber Bragg grating senses ultrasonic vibration and vibration information is modulated into continuous probe light, forms reflected light signal;Optical circulator is oriented transmission to photoelectric converter reflected light signal;Photoelectric converter is converted into electrical signal reflected light signal;Signal acquisition and processing unit carries out synchronous sampling and analog-digital conversion to electrical signal, obtains digital ultrasonic time domain signal;Liquid level inversion unit carries out frequency domain transformation to digital ultrasonic time domain signal, extracts energy attenuation characteristic parameter in preset characteristic frequency band from frequency domain signal, and the liquid level height in container is calculated by the liquid level and ultrasonic energy attenuation quantitative model established in advance.The application realizes non-invasive high-precision liquid level measurement without damaging container structure, and improves measurement stability.

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