This GC series midpoint pressure calculator estimates the outlet column flows through column 1 and column 2, the mid-point supply flow, and the F(1)/F(2) ratio for two capillary columns connected in series with a mid-point pressure supply, based on column geometry, carrier gas, temperature, and pressure conditions.
GC Series Midpoint Pressure Calculator Interface
Connection Diagram
What inputs are required ?
- Dimensions and temperature of capillary column 1 and 2
- Column 1 inlet pressure and column 2 outlet pressure
- Mid-point pressure
- Carrier gas
Outputs of GC Series Midpoint Pressure Calculator
- Outlet flow of column 1 and column 2
- Mid-point supply flow
- Flow ratio between column 1 and column 2
Before You Go
Want to understand how this calculator works behind the scenes?
The full article with explanation is available at GC Backflush Column Setup Explained (Flow Calculation Made Simple) in Gas Chromatography Columns series.
This calculator assumes laminar flow through capillary GC columns and ideal gas behavior at standard reference conditions.
For stable pressure control at the mid-point, the calculated F(1)/F(2) ratio should typically remain below 0.8.
Browse related calculators below:
- Single Column Flow Calculator
- 2 x Columns in Series
- 3 x Columns in Series
- 3 x Columns in Series with Mid-Pressure (1)
- 3 x Columns in Series with Mid-Pressure (2)
- 2-way splitter without make-up supply
- 2-way splitter with make-up supply
- 2-way combiner without make-up supply
- 2-way combiner with make-up supply
If your system uses a different column connection — such as a single column, two-column series, mid-point pressure supply, splitters, or combiners — explore the other GC column flow calculators at Free GC Calculators for configuration-specific flow and pressure calculations.