Optical fiber dissolved oxygen sensing head and preparing method thereof

Abstract

The sensing head is made of plastic optical fiber-polymethyl methacrylate; said sensing head is U-shaped, biconical, biconical + U-shaped, or filament-shaped; on the sensing head the sensitized material is coated. The preparing method is: using the knife to cut off certain length sleeve of the plastic optical fiber; using the alcohol cotton ball to clean up the optical fiber; using the optical fiber to make an optical sensing head in any shapes; putting the optical sensing head into the sol-gel solution; using the crystal pulling method to coat a layer of sensitized material; drying the sensing head in room temperature.

Description

technical field [0001] The invention relates to an optical fiber dissolved oxygen sensor, in particular to an optical fiber dissolved oxygen sensor head for the optical fiber dissolved oxygen sensor and a preparation method thereof. Background technique [0002] Dissolved Oxygen (DO) refers to the dissolved oxygen in water, which is the source of oxygen for animals, plants and microorganisms growing in water. The determination of dissolved oxygen concentration in water is widely used in medical treatment, clinical medicine, industrial treatment, Environmental monitoring and other fields are of great significance, especially in water quality monitoring and water treatment, dissolved oxygen is an important control index, and it is also the most important investigation parameter in water environmental protection, aquaculture and marine science. Optical fiber dissolved oxygen sensor is mainly composed of light source, sensing head, detector and some peripheral circuits. The cur...

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Problems solved by technology

Its disadvantage is that the structure is more complicated, and Y branch optical fiber is required;

[0004] (2) Directly coat the sensitive material on the end face of the silica fiber [see Document 2: A.Campbell, D.Uttamchandani, Optical dissolved oxygen lifetime sensorbased on sol-gel immobilization. IEE Proc.-Sci. Meas.Technol.2004, 151(4):291], but requires a complex optical system to receive light;

[0005] (3) Directly apply the sensitive material to the side of the silica fiber [see literature 3: Brian D.MacCraith, Gerard O'Keeffe, Aisling K.McEvoy, Colette M.McDonagh, Light-emitting-diode-based oxygen sensing using evanescent waveexcitation of a dye-doped sol-gel coating.OPTICAL ENGINEERING1994, 33(12): 3861], but the fluorescent signal received by this sensor head is very little, which is not conducive to the detection

The disadvantage of using the above silica fiber as the sensing head is that the ordinary silica fiber has a thin core and low coupling efficiency with the light source; the shape of the sensing head is relatively simple, which will affect the sensitivity of the sensing; in addition, the silica fiber is fragile, Poor operability

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