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Saturn model 877 Iss.08– 08/14
PRECAUTIONS
Some precautions should be noted as follows:-
1.
Due to the nature that the furnace is used the outer surface will become hot during operation at elevated
temperatures.
2.
Thermal Shock: - The materials used in the furnace have been especially selected for their purity and ability to
withstand Thermal Shock. However, if a cold sensor is introduced into the furnace at high temperatures it
should be inserted slowly, allowing the sensor to warm-up in, say 1cm steps. Failure to observe the above
can cause fracture of the tube into which it was being inserted. If this happens, it will not impair the accuracy
of the rest of the system, but will reduce its capacity. New central equalising spheres are available from
ISOTECH.
3.
Over Temperature: - All the materials used in the construction of the furnace have been rated to 1,400°C.
However, at these temperatures the life expectancy of the heater windings for example are very short. We
therefore recommend an upper temperature of 1300°C for the bath.
4.
Electrical Noise Pick-Up:- At high temperatures all ceramics have a reduced insulation value and hence
conduct more electricity. This means that at temperatures from in excess of 700°C an increasing amount of
‘noise' or electrical interference can be noticed on thermocouple outputs.
Three techniques can be used to eliminate this problem.
The first is to use a filter circuit; the second is to momentarily switch off the furnace heater whilst the
thermocouple reading is taken. Alternatively an isolation transformer can be used to reduce the electrical
leakage.
5.
The furnace must be mounted on a suitable solid flat surface, horizontal to within ±5°.