5.0 Operation
Materials such as case hardening compounds and other reactive salts may penetrate the
furnace chamber lining and attack the wire elements, causing premature failure. Use of
a hearth tile may be advisable: please consult the Carbolite Gero technical department.
5.3
Use of Probes
Any metal object used to probe into the product chamber while the
product is connected to the electrical supply must be earthed. This
applies in particular to metal sheathed thermocouples, where the
sheaths must be earthed. The refractory material of the chamber lining
becomes partly conductive at high temperatures and the electric
potential inside the chamber can be at any value between zero and the
supply voltage. Unearthed probes can cause serious electric shock.
5.4
Atmospheres
When an optional gas inlet is fitted, there is a label near the inlet saying "INERT GAS
ONLY". In practice, inert or oxidising gases may be used, but not combustible or toxic
gases.
The chamber is not gas tight, the gas usage may be high and the chamber is always
likely to contain some air. Residual oxygen of approximately 1% to 2% is to be
expected.
5.5
Operator Safety
This product incorporates a safety switch which interrupts the heating
element circuit when the furnace is opened. This prevents the operator
touching a live heating element and also prevents the product from
heating up if the furnace is left open. The operation of this switch should
be checked periodically.
Depending on use, the surfaces in the working chamber and the
chamber load may still be very hot after the appliance is switched off.
Touching these surfaces may cause burns. Use suitable personal
protective equipment or wait until the appliance cools down to ambient
temperature.
Before removing a hot object from the product, make sure there is a safe place to put it
down. If necessary use tongs, face masks and heat resistant gloves. Heat resistant
clothing and face protection can guard against the effects of radiated heat when the
furnace is open.
When the product is opened during operation there is considerable radiated heat. Do
not keep any flammable objects near the product, nor objects which could be damaged
by radiated heat.
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