18
BÜCHI
Fat Determination
B-820/B-821
Figure 9: Gas saturation bottle with formic acid, 85%
4.5
Filling the formic acid
A small gas saturation bottle is located at the back of the unit,
which must be filled with max. 20 ml of formic acid (85%). The
gas saturation bottle must always contain some formic acid
(85%); do not exced arms of vessel. In this way, it is ensured
that the hydrogen is saturated with formic acid vapor.
The gas saturation bottle must be kept tightly
closed in order to ensure that the hydrogen
system is hermetically sealed.
Caution: The bottle is under pressure
- Do not open when the B-820 is in opera-
tion/hot
- Do not fill up while the B-820 is in opera-
tion/hot
- Do not overfill, max. 20 ml or less 1 cm
below the vessel's arms!
- Only fill when the unit is turned off and is
at room temperature
- Filling under any other circumstances may
lead to system contamination!
4.6
Gas connections
Gases used:
Gas function
Gas type
Setting pressure
Combu
hydrogen 5.0
5 bar (72.5 psi)
separating gas
Auxiliary gas
synthetic air
5 bar (72.5 psi)
Autosampler
synthetic air
5 bar (72.5 psi)
Operating gas
Only use synthetic air, and not compressor air generated and
filtered on-site.
General
Synthetic air and hydrogen from gas cylinders must be equipp-
ed with a two-stage pressure reducing valve. The exit ports of
this valve should be threaded. To enable a precise adjustment
of the output pressures, use a pressure reducing valve with a
measuring capacity of 0 to 10 bar (0 to 150 psi). The output
pressures at the valves to the B-820 unit should be 5.0 bar
(72.5 psi) both for synthetic air and for hydrogen.
4 Putting into operation
Newer instrument models
see mark "-MAX-"
