Thermo Scientific FOCUS GC, Instruction Manual

Page: 126 / 356

Chapter 7
Column
Introduction
126 Instruction Manual
Introduction
The analytical column should be positioned inside the oven. The column ends
should align correctly with the injector and detector base body.
Refer to:
• Capillary and Wide-bore Columns
• Packed Columns
Capillary and Wide-bore Columns
The capillary column should be positioned inside the oven on the column support.
Using Correct Fittings
To connect a capillary column to the injector and detector base body, you must
use the proper column ferrules and retaining nuts.
Column Ferrules
Graphite ferrules are used for many column connections.
• Encapsulated graphite ferrules connect the capillary column to the detector
base body and to the injector.
CAUTION Overtightening compression ferrules does not necessarily produce a stronger,
leak-free joint. In fact, very often the reverse is true. Too much pressure can cause a
leak in the joint and make it very difficult to reseal that particular joint when
changing columns.
Table 7-1 lists the ferrules to use depending on the pre-column and capillary
column external diameter. Ferrules that are the wrong size cause leaks and
contamination.