Quantitative sampling device

Abstract

The invention discloses a quantitative sampling device for liquid or fluid, comprising a mounting frame, an injector, a sampling valve and a displacement control mechanism, wherein the injector is fixed on the mounting frame; one valve port of the sampling valve is communicated with an injector pipeline; and the displacement control mechanism acts on a piston of the injector and controls the piston to move. The quantitative sampling device adopts the injector to quantitatively sample liquid or fluid and accurately controls the amount of the liquid or the fluid to be sampled by controlling thedisplacement distance of the piston of the injector. Compared with the prior quantitative sampling device adopting a quantitative pump or a peristaltic pump, the invention has simpler structure and can greatly improve the quantitative liquid or fluid-sampling accuracy.

Description

technical field [0001] The invention relates to a sampling device, in particular to a liquid or fluid quantitative sampling device. Background technique [0002] Generally, the determination of total nitrogen and total phosphorus includes the following steps: a. Extract the sample to be determined, and add various reagents to the sample; b. Digest in the digestion tank by ultraviolet heating; c. Carry out chemical reaction to remove excess ions ; d. Detect the absorbance of the sample in the detection cell, and calculate it comprehensively with the absorbance of the full-scale standard solution and distilled water (zero point), so as to obtain the pollutant concentration of the sample. In the above-mentioned determination process of total nitrogen and total phosphorus, the amount of reagent added to the sample to be determined must be accurate, otherwise, it will seriously affect the accuracy of the analysis results, which necessarily requires the quantitative sampling devic...

AI Technical Summary

Problems solved by technology

Among them, the quantitative sampling device using quantitative pump sampling is equipped with a sensor to control the amount of reagents taken to achieve the purpose of quantitative sampling. The disadvantage of this device is that it can only measure the reagents passing through the sensor. There are many residual reagents, and accurate sampling cannot be achieved; while the quantitative sampling device using peristaltic pump sampling uses a stepping motor to drive the peristaltic pump, and the purpose of quantitative sampling is achieved by controlling the speed of the peristaltic pump. The defect of this device is that it A pulse flow will be generated during operation, and the error of the sampling result is large

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