Labconco Open Combination (Macro) Kjeldahl Systems 2123Series User Manual
Page 16
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Normal Operation Start-Up
1. The KNA apparatus is designed for use with either 500 or 800-ml
Kjeldahl Flasks. The digestion heaters are free to move forward or
backward on the runway to accommodate either size flask.
2. Turn the heat controllers to the setting on both the Digester and
Distillation racks if both racks will be used simultaneously. Wait
approximately 5 to 10 minutes to insure proper preheating. Sample
chemistry limits the boiling temperature of the sample, so the high heat
setting may be used.
3. Start the acid fume removal blower or water aspirator (depending on
model number purchased). Place a small piece of tissue paper over the
nipple on the digestion manifold. Suction should be
sufficient to hold 2" x 2" (51 mm x 51 mm) tissue paper
in place.
4. Begin the distillation cooling water and check for leaks.
For correct operation of the condensers, the temperature
of the cooling water should not exceed 80°F (27°C).
Watch your thermometer and regulate water flow by
the control valve
5. The inner stainless steel condensing tubes on the
distillation apparatus should be rinsed out by boiling
nitrogen free water in Kjeldahl flasks attached to the
condensation columns before commencing a distillation
procedure.
A generalized Kjeldahl Total Nitrogen method is present in
Appendix C. The method does not detail sample
preparation or preservation procedures, which may be
required depending on specific types of samples.