Photonic crystal fiber optic liquid level sensor and sensing system formed by same

Abstract

The invention belongs to liquid level measurement, in particular relates to a photonic crystal fiber optic liquid level sensor and a system formed by same. The photonic crystal fiber optic liquid level sensor is characterized by comprising a single mode fiber SMF-28 and a photonic crystal fiber SC-4.0, wherein the single mode fiber SMF-28 is fused with the beginning end of the photonic crystal fiber SC-4.0; a beginning end cladding air hole of the photonic crystal fiber is closed at a fusing point to form a beginning end complete collapsing area; the length of the beginning end complete collapsing area is equal to 65 mu m; a fusing machine is used for charging the tail end of the photonic crystal fiber to form a tail end collapsing area; and a reflecting film is plated on the tail end of the photonic crystal fiber. The whole sensor is completely made of optical fibers and has convenient manufacture and no need of optical fiber corrosion. The sensing system is free from the influence of stray light and temperature and has the advantages of less signal noise, high system sensitivity and high reliability.

Description

technical field [0001] The invention belongs to liquid level measurement, and in particular relates to a photonic crystal optical fiber liquid level sensor and a system composed thereof. Background technique [0002] In industrial production, it is often necessary to measure the liquid level. Traditional detection methods include manual methods, float methods, and electrical methods, but these methods have inherent defects in automation, precision, and safety. The characteristics of intrinsic safety and high precision of optical fiber sensor just overcome the defects of traditional methods. Among the many optical fiber liquid level sensors, the light intensity modulation type is the main type, and there are leakage mode [1], total internal reflection based [2]-[5], liquid surface reflection type, etc. However, these optical fiber liquid level sensors also have obvious deficiencies. Some are severely limited by the physical and chemical properties of the liquid to be measure...

AI Technical Summary

Problems solved by technology

[0005] In the existing optical fiber liquid level measurement technology, for liquid level sensing in various environments, corroded optical fiber gratings or tapered optical fibers or optical fiber dislocation fusion splicing are used, which not only reduces the mechanical strength of the optical fiber itself, but also has temperature cross sensitivity. effect, limiting their use

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