5-2
Isotemp Premium Ovens
Fisher Scientific
Section 5
Operation
The 700 Series controllers feature a deviation alarm which alerts the
operator and interrupts heater power whenever the actual oven temperature
differs from the set temperature by more than 5°C. This set limit cannot be
adjusted by the operator.
•
If the actual temperature exceeds the alarm limit, the alarm indicator
LED will light.
•
The reference point for the alarm is the set temperature. Any change in
the set temperature will cause a corresponding shift in the alarm
temperature.
Example:
If the set temperature is 150°C, the alarm will trip at 155°C. If the set
temperature is changed to 200°C, the alarm will follow the set
temperature and trip at 205°C.
•
Changing the set temperature to a value more than 5°C below the
present oven temperature will trip the alarm. Power is removed from
the heater when an alarm condition occurs.
Example:
First, experiment samples were being soaked at 160°C. Experiment
completed and oven reset to 140°C. The oven immediately goes in to
alarm once the set point is reset to 140 from 160. The oven will stay in
alarm until the oven temperature cools down to 144.9° (140,+5,-0.1).
Limit Alarms
