Method for preparing standard gas

Abstract

The invention relates to a method for preparing standard gas, belonging to the technical field of preparation of standard gas. The method comprises the following steps: preparing raw materials, performing gas cylinder pretreatment, calculating the ratio, preparing the gas, verifying and the like. The gas Dalton partial pressure principle and a weighing method are matched with each other, the misunderstanding that the standard gas is prepared according to a single method in the traditional gas preparation technology is avoided, the calculation step is simplified on the quality basis, and manpower and material resources are greatly saved; and moreover, the method disclosed by the invention is simple and reliable, the prepared gas is accurate in concentration and has high industrial application significance.

Description

technical field [0001] The invention belongs to the technical field of standard gas preparation, and in particular relates to a preparation method of standard gas. Background technique [0002] Gas distribution by standard gas weighing method is the most accurate gas distribution method at home and abroad. Because it is based on mass weighing, it can avoid the influence of gas temperature, pressure change and compression factor on the preparation results during the standard gas preparation process. Therefore, this method is recommended by the International Organization for Standardization (ISO) to prepare a standard mixed gas standard method. However, the pressure and mass of the components required by the weighing method in the standard gas operation are completely dependent on the theoretical calculation of the real gas. [0003] At present, there are certain problems in my country's standard gas market, for example, the nominal value is the same as that of N 2 —5ppmO 2...

AI Technical Summary

Problems solved by technology

As required by the contractN 2 -O 2 10×10 -6 , assuming that it is used to calibrate the upper limit of the oxygen analyzer, the calibration gas provided by the producer must be less than 10×10 -6 , exceeding this value, the user may refuse to accept it, so it is easy to cause unnecessary losses to the manufacturer

[0004] In addition, only a single method is used to prepare standard gas in traditional gas distribution technology, such as preparing SO 2 and N 2 During the process of mixing gas, if the moisture in the bottle exceeds the standard, add SO 2 It will cause dissolution. At this time, although the number on the balance is increasing, the SO 2 It does not exist in a gaseous state, and at this time it will seriously affect the quality of the product

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