38
BÜCHI
Fat Determination
B-820/B-821
5.2.5 Preheating/Separation column conditioning
If the unit has been turned off for longer than 30 minutes, the
unit must be preheated for 30 minutes before a determination
or gas flow setup procedure is performed.
If a new column has been installed, the preheating period is 2
hours (separation column conditioning).
Carry out the following steps:
Turn on the gas
Turn on the main power switch to activate the unit. The Büchi
logo appears for approx. 2-3 secs.
This is followed by the user menu.
Enter user name and check the output pressure (5 bar +/-
0.5 bar or 72.5 psi +/- 0.7 psi).
The venting flap closes, the main menu appears and the
pressures build up. As soon as the set pressure values are
reached, the heating elements begin to heat up. The cursor
is positioned on <Preheating>.
The actual temperature and pressure values are displayed on
the right.
p
H2
:
Actual pressure for hydrogen
p
air
:
Actual pressure for synthetic air
T
Oven
: Actual temperature for oven
T
inj.
:
Actual temperature for injection heating
T
FID
: Actual temperature for the flame ionization detector (FID)
Enter the preheating time of 1800 secs (or 7200 secs if the
column needs conditioning). The preheating procedure cannot
be started until the entered set pressure values and set
temperatures have been reached. (Ready LED must be
permanently lit). If this is not the case, an error message will
appear.
Preheating
p H2
55kPa
Sample weight/Mode
p air
50kPa
Determination
T oven
130°C
Data manager
T inj.
220°C
Setup
T FID
260°C
S
W
I
T
Z
E
R
L
A
N
D
Version: 3.00af
Gas supply on?
User: C.Heiter
Press
<ENTER> to cont.
S
W
I
T
Z
E
R
L
A
N
D
5 Operation
