21
BÜCHI
Fat Determination
B-820/B-821
4.8
Installing the separation column
1. Open the oven door
2. Position the seals, screws and nuts as shown in Figure 11.
3. Figure 12 shows how to fit the separation column. Push
both sides of the column up as far as they will go, hold in
place and tighten nuts by hand.
4. The two nuts must be tightened by ¼ to ½ turn using the
supplied spanner (17”).
Take care not to overtighten nuts as this could break the
glass.
Figure 11: Positioning seals and
screw nuts
Separation column installed
Installing the separation column
4 Putting into operation
The procedure is the same for
the "Fatty Acid column"
Figure 12: Installing the colums
The column should be heated only when gas (H
2
) is flowing.
Prior to operation, always ensure that the gas supply is opened.
When fitting a new column, always ensure that there is a
septum in the injection head.
After a long period of use (approx. 1,000 injections), the injec-
tion zone of the separation column can become soiled, which
can impair the reproducibility of the individual measurements.
A
new
column must be conditioned before doing any opera-
tions. This requires a
preheating period of 120 min.
(see
Section 5.2.5, "Preheating/Separation column conditioning“).
The results of the first two injections using a new column can
vary greatly. Therefore, these values should be ignored.
