FBG (fiber bragg grating)-based multifunctional flow sensor provided with embedded standard nozzle

Abstract

The invention relates to an FBG (fiber bragg grating)-based multifunctional flow sensor provided with an embedded standard nozzle. The flow sensor comprises parts such as a main valve provided with the embedded standard nozzle, a pressure obtaining cavity, an alloy diaphragm, a sealing end cover, a pressure sensor, a temperature sensor and the like. The flow sensor adopts a special structural form of surface and end cover dual-sealing and the design of a specially-shaped gasket: three groups of FBGs with different central wavelengths are selected and used for measuring flow, pressure and temperature parameters of a fluid respectively, and a public interface is formed outside by the aid of an optical fiber coupler, so that the unique advantage of wavelength coding of the FBGs is fully used. Meanwhile, the FBG-based temperature sensor can be used as a reference grating, and the problem of cross sensitivity of the FBG to the temperature and the strain is solved. The FBG-based flow sensor has multiple functions and is compact in size, convenient to mount, flexible to apply, capable of facilitating further function expansion and widely applicable to fields of state inspection of hydraulic systems and the like.

Description

technical field [0001] The invention relates to a multifunctional flow sensor for fluid measurement in a hydraulic system, in particular to a fiber grating embedded standard nozzle multifunctional flow sensor capable of simultaneously measuring pressure and temperature, and belongs to the technical field of optoelectronic measurement. Background technique [0002] In industrial production and engineering applications, fluid flow is one of the parameters that need to be frequently measured and controlled. Due to the limitation of the mechanical structure, the traditional mechanical rotameter has a large measurement error. The electromagnetic flowmeter, ultrasonic flowmeter and acoustic Doppler flowmeter developed later, although the test accuracy has been improved, but they are susceptible to electromagnetic interference and the cost of use is relatively high. Fiber Bragg Grating is an emerging photonic device that uses the spatially periodic refractive index distribution fo...

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Problems solved by technology

[0005] In view of the above-mentioned prior art situation, the object of the present invention is to overcome the deficiency that the existing fiber grating sensor is only aimed at the single parameter measurement, and provide a sensor that is easy to install, easy to seal, and can measure the flow rate, pressure and temperature of the measured fluid at the same time. Parameters are measured simultaneously, and a sensor capable of solving the temperature-strain cross-sensitivity problem of fiber gratings

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