Thermo Scientific FOCUS GC, Instruction Manual

Page: 150 / 356

Chapter 7
Column
Keeping Leaks Under Control
150 Instruction Manual
Expected K Factor
The following tables indicate the expected K factors for columns of ideal
dimensions when using helium, hydrogen, or nitrogen as a carrier gas.
Use this information when interpreting results from a Column Evaluation.
Deviations of 10-15% from the value reported in this chart are normal and occur
due to dimensional tolerances.
For example, a 30 m x 0.25 mm column will typically give K factors of 1.5–2.0.
Large deviations from the expected values will indicate leaks in the septum or
column ferrule or a plugging of the column at the inlet or exit points.
NOTE Porous layer open tubulat (PLOT) columns will exhibit actual K factor higher than the
expected values, depending on the particles packing.
K Factor Tables
• Helium Carrier Gas Theoretical K Factor
• Nitrogen Carrier Gas Theoretical K Factor
• Hydrogen Carrier Gas Theoretical K Factor
COLUMN EVALUATION
Err! Too low P drop
COLUMN EVALUATION
Err! Too High P drop.