Performance evaluation of mixed gas standards

1. Inspect the uniformity of mixed gas standard samples

The uniformity of the standard gas will directly affect the accuracy of its component content. For this reason, the prepared standard gas must be homogenized. Place the prepared steel cylinder on the rolling device and roll it for 2 hours to make it fully mixed. It can be measured by the change of the component content of the gas chromatography, and its uniformity can be determined by the method of variance analysis. In addition, after the preparation of the gas standard substance is completed, it is in a uniform state after 2 hours of homogenization treatment, and the gas standard substance has good uniformity.

2. Investigation of pressure stability of mixed gas standard sample

The mixed gas in the cylinder will cause stratification due to the different molecular weights and boiling points of the components. After a long time of rolling, stability experiments must be carried out.

3. Investigation on the stability of mixed gas standard samples over time

As a standard sample of mixed gas in nitrogen, it must be stable for a long time, and the content of its components will change within the allowable range. For this reason, long-term stability investigation should be done.