Carbolite CAF 16/38 - Manual (Page 7)

CAF16
MF45 1.05
7
Note: Do not operate the furnace at temperatures above 815

C (1499

F) with the door open.
The furnace door must not be left open longer than is necessary to load and unload samples from
the work tube.
Sample tiles can be obtained from Carbolite. A brass mould to assist with forming samples is
supplied with the furnace.
3.3 General Operating Advice
Heating element life is shortened by use at temperatures close to maximum. Do not leave the
furnace at high temperature when not required. The maximum temperature is shown on the
furnace rating label and on the back page of this manual.
Light weight ceramic fibre insulation can easily be marked by accidental contact. Some fine cracks
may be visible on the surface of the insulation, or may develop in the surface of the chamber due
to the progressive shrinkage of the insulation materials. Cracks are not usually detrimental to the
functioning or the safety of the furnace.
3.4 Tube Life
The following applies if the furnace is used for a purpose
other than its standard application.
A work tube may be cracked if workpieces are inserted too
quickly or at temperatures below 900°C (when the tube is
more brittle). Large pieces should also be heated slowly to
ensure that large temperature differences do not arise.
Poor thermal contact should be encouraged between the
workpiece and the tube; crucibles or boats should be of low
thermal mass and should have feet to reduce the contact with the tube.
Avoid metal directly touching the work tube - see the safety warning below.
3.5 Operator Safety
The ceramic materials used in furnace manufacture become electrically conductive to some extent
at high temperatures. DO NOT use any conductive tools within the work tube without isolating it.
Warning: Do not use the furnace if the work tube is cracked as there is a risk of exposure to
carbon monoxide gas. See section 1.4: Carbon Monoxide Warning.