CDF
MF56 – 1.05
5
material of the chamber lining becomes partly conducting 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.
3.4
Atmospheres
Chamber furnaces are not gas tight, so it should be understood that gas usage may be high, and that
the chamber is likely always to contain some air. Residual oxygen levels of 1% are to be expected.
In practice
inert
or
oxidising
gases may be used, but
not combustible or toxic gases
.
3.5
Operator Safety
The furnace incorporates a safety switch which interrupts the heating element circuit when the
door is opened. This prevents the user touching a live heating element, but also prevents the
furnace from heating up if the door is left open. The operation of this switch should be checked
periodically – see section 4.1.2.
Avoid burns: furnace surfaces can be hot. Before you remove a hot object from the furnace make
sure you have a safe place to put it down.
