BUCHI SpeedDigester K-436 - Manual (Page 34)

6 Operation
34 K-425 / K-436 Operation Manual, Version A
6 .2 .5 Starting up the SpeedDigester
System preconditions
The system must be correctly installed and fully functional. All parts must be in proper condition (e.g.
clean and free of damage). See also section 2.5 “Product safety” for general warnings!
Start-up procedure
Select and install insulation plate(s) according to the type of sample tubes. •
Install insulation caps at unused positions of the insulation plate(s) for 300 / 500 ml racks. •
Make sure the SpeedDigester K-425 / K-436 is properly connected to the mains supply. •
Start the ventilation of the fume hood. •
Switch on the SpeedDigester K-425 / K-436 at the mains switch at the front. •
The heating level can now be set via the corresponding thermostat knob. •
Note
For operation with 3rd party sample tubes no insulation caps and glass caps are available. Hence, all
positions must be equipped with samples!
6 .3 Performing a Kjeldahl digestion process
This section is divided into two consecutive sub-sections (6.3.1 and 6.3.2) and follow-up actions in
section 6.5. Do not skip or mix up these steps to ensure safe handling and best performance.
Note
Application notes are available for various samples at Buchi. These notes work as digestion recipes
and give detailed instructions how to process specific sample materials. For application notes,
contact your Buchi application specialist or your local distributor.
6 .3 .1 Preparational steps
Start-up the SpeedDigester. 1.
Set the required preheating temperature and let the system heat up 10-15 minutes minimum. 2.
Prepare the sample tubes according to the type of digestion under safe conditions. 3.
➡ The samples are now ready to be digested.
6 .3 .2 Starting a digestion process
Install the rack(s) according to the chosen sample tube size. 4.
➥ Place glass caps (order no. 040049) into every unused position of the rack
➥ Place insulation caps into every unused postion at the insulation plate
➥ To securely withdraw harmful fumes, switch on the suction unit (Scrubber or water jet pump)
before inserting the racks into the instrument!
The digestion process starts, as soon as the sample tubes heat up in the instrument. 5.
➥ Depending on the sample material and acid / catalyst composition it might be necessary to vary
the digestion temperature at different time intervals (digestion program).
At the end of the digestion switch off the instrument via the mains switch. 6.
➡ The samples are now digested. Follow-up actions are described in section 6.5.