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Furnace Loading
During tuning, the lower display flashes between "tunE"
and the setpoint temperature. The setpoint temperature
can be changed during tuning by pressing the UP or
DOWN buttons. The lower display will continue to flash
until the tuning is completed.
Be sure to use care in loading and unloading the fur-
nace chamber. Molybdenum disilicide heating elements
are extremely fragile and can crack or break with just a
slight bump. Be sure not to block the flow of radiant
heat from the heating elements to the thermocouple.
The thermocouple must be able to respond directly to
the heating elements. Failure to observe this will permit
the heating elements to overheat and possibly burn
out. Poor temperature control can also result from
improper loading.
Because of the possibility of erosion of the insulation
on the floor of the furnace chamber, a separate hearth
plate should be used when possible.
In general, space should be left on all sides of a load
or on all sides of individual components of a load so
that heat can penetrate through the surfaces. The load
should not occupy more than two-thirds of the inside
dimensions of the chamber.
The extent to which a furnace may be loaded depends
upon such factors as operating temperature, desired
accuracy, and type of material. A furnace may be
loaded more heavily at lower temperatures, if highest
accuracy is not needed, and if the material of the load
absorbs heat easily.
Furnace Atmospheres
This furnace is designed to be used to 1700°C in pure
air only. It may be used with nitrogen, argon, or helium
atmospheres to 1600°C. Reducing atmospheres are
not recommended.
The heating elements in this furnace are attacked by
fluorine, chlorine, sodium and potassium compounds
and also by molten metals. This furnace may be used
for metal melting if care is taken not to splash molten
metal on the heating elements.
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