By Anonymous on Tuesday, June 24, 2003 - 05:20 am:
All-
What is the purpose of makeup gas flow when using an FID, and does 25 mL/min sound like a normal setting for it (using He as carrier)?
Thanks in advance,
-Jeff
By Anonymous on Tuesday, June 24, 2003 - 09:28 am:
When the classical FID was created its performance was optimized at typical column flow rates at the time. Packed columns were the standard and their flow rates were usually around 30ml/min. When capillary columns were introduced at much lower flow rates it became necessary to "make-up" the difference. Thus additional flow was needed and that brings the total flow off the end of the column back to around 30 ml/min.
By vijay on Saturday, July 19, 2003 - 02:37 am:
hi
pe instruments don't have this option.
now-a-days all mordern gc's the hydrogen (30 to 40 mL/min.) flows through the fid and flesh all the eluting components from the column and may be the above option works out
vijay
By carla on Wednesday, November 26, 2003 - 03:32 am:
The use of nitrogen as make-up when using a FID is optional, but allows us to obtain a more robust flame, therefore stabler
By Anonymous on Monday, January 12, 2004 - 12:03 pm:
PerkinElmer GC's don't need a makeup for their FID due to a patented design that allows the air to act as the make up gas.