Instruction manual

Operation
How to use the FUNCTION field
2-58 WX Ultra Series Thermo Scientific
Defrost function
If the chamber door is left open between low temperature runs, moisture from the ambient air
humidity can condense (and even freeze) on the cold evaporator chamber walls. The potential for
condensation increases as the ambient air temperature and humidity increases. If a run is performed
with a significant amount of moisture in the evaporator chamber, the length of time required to reach a
high vacuum will be increased.
To minimize condensation, when the evaporator chamber is cold, we recommend that you keep the
chamber door closed as much as possible. If moisture does accumulate, before performing the next run,
we recommend that you wipe the chamber dry. For situations where condensation has frozen to the
chamber walls, a defrost function is provided as a convenient means to melt ice buildup so that the
moisture can then be removed.
How to use the defrost function:
Defrost operation will heat the evaporator gradually and after the lapse of 10 minutes, the defrost
operation and vacuum ends automatically. (After the end of the defrost operation, the DEF display in
the message field disappears.) During the defrost operation, DEF in the message display field in the
bottom row on the Run Screen blinks. To abort or end the Defrost Function, highlight DEF and press
ENTER. To turn off vacuum, press vacuum key.
Note When the ω
2
T display field reaches the set value of ω
2
T, the machine decelerates and stops.
During deceleration, the
ω
2
T display field continues to accumulate value until the rotor stops and
the run ends.
Step Key operation Screen display and considerations
1 Use cursor keys to move the cursor to
DEF on the Run Screen.
2 With DEF highlighted, press the ENTER
key.
• Use cursor keys to highlight
the DEF function.
• DEF blinks in the message
field to notify that a defrost
operation and vacuum has
started.
• Vacuum indicators will also be
displayed.