Total Flow

Hi camelia,

The total flow in split flow  equation( Total flow =septum purge vent+ split vent+ column flow) ,So I think the difference in septum purge vent value, for method 1 the septum purge vent equal to 2.2ml/min and for method 2 equal to 1.1

check septum purge vent will solve the  puzzle

Another thing look a little and recommended septum purge vent 3ml/min 

  Dheya 

Hi Dheya,

the calculated septum purge value for method 1 with a total flow of 196.6 is 2.2 (196.6-194.4) and for method 2 with a total flow of 197.1 is 2.4 (197.1-194.4). The split flow (192) and column flow (2.4) is the same for both methods. I do not want to change the split vent flow in either method as I need to maintain the same split ratio for both methods (192/2.4=80)

Using your thoughts however, If the total flow for method 1 is increased from 196.6 to 197.4 (0.8 increase) the calculated septum purge would then be 3. Likewise if the total flow for method 2 is increased from 197.1 to 197.4 (0.3) the calculated septum purge would then be 3. I would like to try this and see what the software does. As long as it doesn't affect either the split flow or column flow this may be a way to control the septum purge even though it is not settable in the method. 

Maybe somehow the methods have been corrupted and writing again from scratch using the same split flow (192), column flow (2.4) and the same adjusted total flow (197.4) for both methods would give the recommended 3 ml septum purge and the expected consistent total flow between methods. 

Thank you and kind regards,

Camelia

Hi Dheya,

the calculated septum purge value for method 1 with a total flow of 196.6 is 2.2 (196.6-194.4) and for method 2 with a total flow of 197.1 is 2.4 (197.1-194.4). The split flow (192) and column flow (2.4) is the same for both methods. I do not want to change the split vent flow in either method as I need to maintain the same split ratio for both methods (192/2.4=80)

Using your thoughts however, If the total flow for method 1 is increased from 196.6 to 197.4 (0.8 increase) the calculated septum purge would then be 3. Likewise if the total flow for method 2 is increased from 197.1 to 197.4 (0.3) the calculated septum purge would then be 3. I would like to try this and see what the software does. As long as it doesn't affect either the split flow or column flow this may be a way to control the septum purge even though it is not settable in the method. 

Maybe somehow the methods have been corrupted and writing again from scratch using the same split flow (192), column flow (2.4) and the same adjusted total flow (197.4) for both methods would give the recommended 3 ml septum purge and the expected consistent total flow between methods. 

Thank you and kind regards,

Camelia

Hi All,

I changed the total flow but as this affected the split ratio and the split flow it is not a viable option.

I also created the 2 methods from scratch using the total flow value of 196.6 for both methods whilst maintaining the same split flow and split ratio. 

I can only think that there was some "glitch" in the software in the original method so i have marked the response from James as the correct answer to close this post off.

Many thanks