64
BÜCHI
Fat Determination
B-820/B-821
9 Appendix
If the measuring results continue to deteriorate, check the
following possible sources of error:
1. Extraction procedure insufficient (e.g. time)
2. Poor gas quality
3. Sufficient formic acid in the bottle
4. Separation column possibly defective or worn
5. Preheating time too short
6. Incorrect mode selected
7. Incorrect sample weights entered
8. Incorrect factor entered
9. Faulty injection technique
10. Incorrect injection volume
11. Air injected
12. Injection needle not fitted securely
(solution is leaking from needle)
13. Needle clogged
14. Insufficient flow rate
15. FID dirty
Before you assume that the Autosampler B-821 is faulty, make
one or more injections by hand. If the problem remains, check
the Autosampler. While it is frequently assumed that the
sampler is defective, the problem may rather be caused by
the B-820 unit.
9.3
Materials used
Description
Materials:
Oven Insulations:
Doors:
Insultherm 550
Exhaust:
Insultherm 550
Air inlet:
Insultherm 550
Exhaust duct:
Insultherm 550
Exhaust flap:
Insulglatex 620
Top:
Insultherm 550
Bottom:
Insultherm 550
Back:
Insultherm 550
Sides:
Microtherm
Foil keypad:
Carousel (B-821)
Polymerplastic
Various lines (B-821)
PTFE
Other materials used:
Metals:
Steel, aluminium, brass
Glass parts:
Soap bubble meter of
borosilicate glass
Separation column of
borosilicate glass
Gas saturation vessel of Pyrex
Electrical components:
Various printed circuitboards,
hot-air fan,
axial ventilator, lifting magnet
Table 12: Materials
