BUCHI Extraction System B-811 LSV - Manual (Page 36)

6 Operation
36 B-811 Operation Manual, Version G
6 .2 Preparing for an extraction
To prepare the instrument for an extraction, proceed as follows:
Turn the condenser to the right and release it. 1.
Press the stop key, the condensers move out. 2.
Insert the glass sample tubes/thimbles into the sample holders. 3.
Pull the condensers down with both hands (see Fig. 6.5) until they clicks into place. 4.
Close the condenser by turning it to the left. 5.
Set the height of the optical sensor (solvent must cover the sample). 6.
Fill the solvent beaker and assemble it. 7.
Activate the lower heating element by pressing it up. 8.
Open the cooling water (tap water/chiller). 9.
Select a stored program or program a new one. 10.
Start the program. 11.
6 .3 Soxhlet Standard Mode - programming example
Program description:
A standard extraction according to the original Soxhlet extraction is carried out. The solvent level is
detected by the optical sensor, the magnetic valve opens and the solvent is released into the beaker.
Solvent: petroleum ether 40/60, for other heating levels see chapter 6.11.
Function key Display Description
SELECT The Mode display
blinks
Select the Soxhlet Standard Mode using the / keys
Display STEP 1 blinks (STEP 1 = Extraction)
Display HEATING
blinks
Select the heating level (1 - 20) using the / keys
Select level 9 for petroleum ether 40/60
Display CYCLES
blinks
Select the number of cycles using the / keys
If the number of cycles = 0 is entered, then the extraction is
finished when the extraction time has expired
Display H: MIN blinks Select the extraction time (0 - 99:99 h) using the / keys
If no time is entered, then the extraction is finished when all posi-
tions have completed the set number of cycles
If both parameters are entered (time and number of cycles), then
both criteria must be fulfilled before the instrument switches to
the next step
Display STEP 2 blinks (STEP 2 = Rinsing)
Display HEATING
blinks
Select the heating level (1 - 20) using the / keys
Select level 9 for petroleum ether 40/60
In case of oxygen-sensitive analytes, the gas supply must be
activated by pressing the INERT GAS key
The inert gas valve is automatically opened up while the step
starts