BUCHI Wet Digester B-440 - Manual (Page 14)

4 Description of function
14 B-440 Operation Manual, Version D
4 Description of function
This section explains the basic working principle of the Wet Digester B-440. It also shows how the
instrument is structured and provides a general functional description of its assemblies.
4.1 Functional principle
The set-up with the optional condensate trap is suitable for all wet ashing operations (e.g. when using
sulphuric acid). The ratio between the weight of the sample / acids and the temperature program must
be selected in such a way that practically only gaseous products are produced by the reaction.
Digestion process overview

Glass hood
Vitrifi ed
ceramic plate
Acid vapor outlet
to Scrubber

Condensate trap
Activated
charcoal
Corrugated
hose
Processing steps:
The infrared heating s 
Inside the crucibles s  the digestion process of the sample material takes place.
Hot fumes s
Scrubber.
The digestion fumes can be highly corrosive and hazardous to life forms! The optional condensate s
trap can be interconnected between the glass hood and the scrubber
hazardous fumes in the fi rst place.
The activated charcoal must be kept in place within a sandwich layer of glass wool s at each end
of the condensate trap.
Every glass-to-glass connection must be secured by a clip s !