Precautions for standard gas in sample injection:

The particularity of standard gas has special requirements for sampling. Many users have great data deviation due to non-standard sampling. Several aspects should be paid attention to when providing sample sampling:

1. the selection of sampling pipeline, because the hose is very convenient to use, many traditional injection pipelines are used, but as we all know, the hose for most organic gas, and sulfur gas adsorption is very strong, and its permeability is also very strong, so the use of all kinds of hose to sample is not desirable, caused a great deviation to the analysis data. It is recommended to use copper tube, stainless steel tube and tetrafluoride tube according to different gas properties, and it is best to use quartz coated stainless steel tube for standard gas and sample gas containing sulfur.

   
   

2. the replacement of sample gas, because the standard gas can only be sampled after the pressure reducer and pipeline, to accurately sample the pressure reducer and pipeline must be fully replaced, this replacement is not a simple sense of purge. Because the dead volume of the decompressor is very large, the steel cylinder valve is opened and closed repeatedly more than 3 times, each time the gas in the decompressor is drained, and then the purge system can be sampled correctly.

3. The air tightness of the injection pipeline and the leakage of the injection pipeline have a great impact on the accuracy of the sample data, especially on the low concentration of oxygen. Therefore, the air tightness of the sampling line must be strictly checked.

4. It is most undesirable to try to take the standard gas from the standard gas cylinder to the sampling bag or other container, and then sample and analyze it from the container, which causes secondary pollution. So that the sample gas data can not be truly represented.