ELTRA CS-2000, Руководство пользователя

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Analysis
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Fig. 15: Crucibles preheating
The above furnace is used for preheating crucibles. It is an optional accessory and can be
purchased separately.
When analyzing samples with low concentration of carbon or sulfur (<1000 ppm), the pre-
heating of the crucibles is advisable.
The crucibles contain traces of carbon, which can vary from 20 to several hundred ppm,
depending on their quality. Additionally, this blank value is not constant; it can be different for
different crucibles. These problems, of course affect the accuracy of the analyses, therefore by
pre-heating the crucibles, their carbon impurities will be largely eliminated. The remaining blank
value therefore, will be very low and it will remain fairly identical for each crucible. This is
important for keeping results deviations low.
5.4.1 Operating the pre-heating furnace (optional)
Fig. 16: Operating the pre-heating furnace
NOTICE
Do not move more than 4 crucibles at a time into the furnace. Otherwise the combustion tube
may break, due to temperature shock caused by incoming cold crucibles.
Set temperature: 1000°C
After five minutes feed-in the next four crucibles if needed(C).
Up to 22 crucibles fit inside the furnace. (B) is the hot zone inside the furnace.
When entering new crucibles into the furnace for preheating, an equal number of preheated
crucibles will fall off the other end (A) of the furnace tube.