Metering tube piston head structure for high-accuracy analysis meter

Abstract

The invention relates to a metering tube piston head structure for a high-accuracy analysis meter. The metering tube piston head structure comprises a piston top cover, a hard lining, a sealing ring and a body. The hard lining is fastened in an annular groove of the piston top cover through the inner lateral wall of the annular body, the sealing ring is installed on the outer lateral wall of the lining and in a space formed by the annular groove of the piston top cover, a short shaft of the piston top cover is screwed in a screw hole at the position of the axis of the body, and the upper end face of the body is contacted with the surface of the sealing ring. The metering tube piston head structure has the advantages of adopting teflon to manufacture a piston, simultaneously utilizing the hard lining and the elastic sealing ring, enabling a piston to have proper plasticity and further improving contact sealing performance of the piston and the metering tube wall due to the fact that fine edges are arranged on the outer lateral cylindrical face of the piston top cover. The piston adopts a split structure, and users can simply replace the piston top cover after the piston is damaged. The head structure is reasonable in structure, corrosion-resistant, abrasion-resistant, small in leakage rate and capable of being popularized and used in devices of various analysis instrument metering tubes.

Description

Technical field: [0001] The invention relates to a research technology of the physical or chemical properties of a material, in particular to a piston head structure of a metering tube used in an analyzer. Background technique: [0002] An electrochemical titrator is usually composed of a sampling unit, a titration unit, a measurement unit, and a control unit. The sampling unit and the measurement unit usually use a high-precision metering tube with a piston to accurately calculate the titration reagent added to the measurement system. , the measurement accuracy of the titrant volume represents the measurement accuracy of the entire system, and the service life and precise movement of the piston head in the metering tube have a decisive influence on the measurement accuracy. In the prior art, the common piston head is tightly fitted between the O-ring and the quantitative tube, and the sealing is ensured by the friction and pressure between the sealing ring and the quantitat...

AI Technical Summary

Problems solved by technology

The disadvantage of this structure is: the material of the sealing ring is difficult to choose, the hardness of the sealing ring is directly related to the friction between the piston and the measuring tube, and some highly corrosive reagents will damage different sealing rings. Cause the piston to crawl, or the control motor will be blocked or out of step due to too much resistance, which will seriously affect the measurement accuracy, resulting in inaccurate measurement results

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