Watch the sample and record the temperature at which it fuses. Make all other records
such as time and temperature as required by your own organisation.
Switch off and allow to cool down; or set the setpoint to zero or to the normal test
starting temperature, so that the temperature is displayed as the furnace cools.
Note: Do not operate the product at temperatures above 815 °C (1499 °F) with the
door open. The product 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 Gero. A brass mould to assist with forming
samples is supplied with the product.
5.3
General Operating Advice
Heating element life is shortened by overheating. Do not leave the
product at high temperature when it is not required. The maximum
temperature is shown on the product rating label and in section 11.0
towards the back of this manual.
Lightweight ceramic fibre insulation can easily be marked by accidental
contact. Some fine cracks may develop in the surface of the insulation
due to the progressive shrinkage of the insulation materials. Cracks are
not usually detrimental to the functioning or the safety of the product.
5.4
Tube Life
A ceramic work tube may crack if work pieces are inserted too quickly or at
temperatures below 900 °C (when the tube is more brittle). Large work pieces
should also be heated slowly to ensure that large temperature differences do not
arise.
Poor thermal contact should be encouraged between the work piece and the tube;
crucibles or boats should be of low thermal mass and should have feet to reduce
the contact with the tube (fig. 4).
Key
A
Tube
B Crucible
Fig 4 - Avoidance of thermal contact
17
5.0 Operation
