On the determination of the shunt ratio
Thread Content
Hello everyone. I need to measure the split ratio of gas chromatography, but there are a few concepts that I’m not quite clear about, so I’d like to ask for your advice. Is column flow rate the flow rate entering the column? . . How do I measure this? . It is still calculated by subtracting the shunted flow from the total flow. . What is the relationship between the total flow rate and the pressure before the column? . Are the two equivalent? . My instrument manual includes the conversion between pre-column pressure and flow rate. . . My instrument has two outlets: one for the \"split stream\" and one for the \"cleaning stream\". If I just want to roughly determine the split ratio, how should I do that? . Thank you all. .
Because I can’t really understand the instructions either. . . So there was no choice but to seek help
I can use a soap film flow meter to measure the flow rate of the stream that is diverted. What’s confusing me is how to determine the total flow rate and what the pressure before the column refers to. I think the column flow rate can be obtained by subtracting the diverted flow rate from the total flow rate; I just want to make an approximate measurement. . .
What kind of instrument? Could what comes out after cleaning be the backflow?
Reply to 1# Huayan: The pressure before the column is the total carrier gas pressure prior to diversion; the total flow rate can be determined using the pressure-flow curve provided in the manual. The split ratio is the ratio of the flow rate of the carrier gas entering the column to the flow rate of the carrier gas being vented. It is generally between 1:10 and 1:100; for example, if the total flow rate is 11 ml/min. If the split ratio is 1:10, then the flow rate into the column is 1 ml while the flow rate discharged is 10 ml.