Atmosphere Port; Option B (Excess Temperature Controller) - Thermo Scientific BF51841C Operation Manual

Operation

Atmosphere Port

Atmosphere Port
The BF51841 furnace has a factory-installed air/atmosphere port.
Most inert atmospheres (i.e. nitrogen, argon, and helium) can be safely run in the
BF51841 box furnace. However, maximum temperatures may be derated
depending on atmosphere. An initial burn in period in air is recommended. Please
contact Thermo Fisher Scientific prior to using the furnace with an inert
atmosphere.
The furnace should be run for 7-10 hours at 1100 °C before using an inert
atmosphere and after every 60 hours of use with an inert atmosphere. This burn in
process will help remove contaminants and provides a protective oxide layer on
the heating elements.
The BF51841 furnace is not designed to be a gas-tight atmosphere furnace.

Option B (Excess Temperature Controller)

The over-temperature protection system (option B) is a redundant over-
temperature protection system which utilizes a separate controller, magnetic
contactor and thermocouple.
For protection of the furnace the over-termperature alarm setpoint should be set
slightly higher than the furnace maximum operating temperature. To protect the
furnace load set the alarm setpoint higher than the working temperature but below
the critical material temperature.
If an over-temperature condition occurs, an alarm will be displayed and the
heating element power will be disconnected until the controller is reset manually.
The front panel is similar to the UT150 temperature control panel (Refer to
"Heating Unit
For detailed instructions, refer to
5-2
Replacement").
Section "Excess Temperature
Figure
Option".
Thermo Scientific