Buchi K-424, Руководство по эксплуатации

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9
Digestion Unit K-424
5 Operation
5 Operation
5.1 Operating elements
Main switch
Energy regulator
Heater pilot lamp
Mains connector
5.2 Operating elements and their function
Main switch
Switching the apparatus ON/OFF. In case of an mains load
over 12 A a bimetal switch cuts the circuit causing the
mains switch switching to OFF.
After switch back to ON the apparatus is ready to operate
again.
Energy regulator
Regulates the heating in stages from 1 -10.
5.3 General information
The heating process heats the digestion tubes uniformly
from the side, leading to good boiling behaviour (no
retardation of boiling). Boiling chips are used only when
larger quantities of water (>10 ml) are evaporated (no glass
beads used).
It is important that the condensation zone of the sulfuric
acid does not rise too high ( maximum 5 cm under the
glass rim).
For the digestion of approx. 1 g of organic material, normally
18 - 20 ml H
2
SO
4
are used.
For each additional gramm of organic material an addition
of 3 - 5 ml (by fat or mineral-oil 5 - 10 ml) H
2
SO
4
has to be
used.
Fig. 6: Arrangement of the control and display elements rear
Fig. 5: Arrangement of the control and display elements front
Fig. 7: Condensation zone of the sulfuric acid