Metrohm 743 Rancimat - Manual (Page 88)

4.6 Determinations ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
80 ￭￭￭￭￭￭￭￭ 743 Rancimat
Check and prepare the instruments and vessels as follows (see also figure
5, page 14):
1 Check openings for reaction vessels
￭ Check whether the openings are clean and empty. Blow the dust
out of the openings with nitrogen.
If the instrument is not used, always seal the openings with the
sealing plugs.
2 Fill the measuring vessels
Note
Only use measuring vessels and accessories which are abso-
lutely clean and in a perfect condition.
￭ Fill the cleaned measuring vessels with 60 mL distilled water
each.
For analysis times > 24 h approx. 7 mL more distilled water must
be added per day to compensate for the evaporation loss, so that
the electrodes remain safely immersed.
3 Insert the measuring vessels
￭ Place the clean measuring vessel covers equipped with a PTFE
tube on the measuring vessels.
￭ Insert the measuring vessels with the measuring vessel covers into
the openings provided for this on the 743 Rancimat and, at the
same time, carefully guide the connection plugs (5-15) of the
cover carefully into the electrode connectors (3-2).
4 Weigh in the sample
Note
Use new reaction vessels and air tubes for each measure-
ment. Blow the reaction vessels out with nitrogen before use so
that any particles adhering are removed.
￭ Weigh in 3 g of the prepared samples in each of the reaction
vessels (see Chapter 4.6.1, page 76).