BUCHI SpeedExtractor E-916 - Manual (Page 44)

6 Operation
44 SpeedExtractor E-916/E-914 Operation Manual, Version D
Reference setting for a standardized leak test
Description Value
Temperature 100 °C
Pressure 100 bar
Solvent ethanol
Hold time 4 min
Extraction cell all volumes
Expansion element, sand Expansion element 2–120 mL (refer to chapter 10) or
sand
• Set the reference settings:
Open MENU  LEAK TEST. Instead of copying the
entries of the CURRENT METHOD, set the refer-
ence settings according to the table above. For
the TEMPERATURE, set 100 °C using the selec-
tion knob. Press OK. The cursor skips to the next
entry. Proceed similarly to set 100 bar and 100 %
ETHANOL.
Press START to run the leak test.
• As described for the method-based approach, the
presence of the cells is first checked using nitrogen
(7 bar) before the set pressure (100 bar) is reached.
Evaluation of leak tests
The absolute values depend on different parameters. These are: Set temperature and pressure, used
solvent, cell size, and cell filling. When the following criteria are fulfilled, the instrument can be consid-
ered as tight and in good conditions:
• Maximum pressure difference between the positions does not exceed 15 bar.
• The pressure of the positions and the overall pressure has to be at least 95 % of the set pressure.
• The overall pressure should drop after reaching the set pressure while the individual position
pressure(s) increases slowly. The overall pressure should not rise until the difference between
overall pressure and position pressure(s) reached min. 25 bar. After this the overall pressure is al-
lowed to rise and to follow the position pressure(s).