Operating Manual - John Morris Scientific

Ultra-Low Refrigerated Circulators
>SafeTemp:<
IntMax: and IntMin: Limit setting
Setting range: see working temperature range
The limits IntMax and IntMin are only valid for external control. IntMax and
IntMin are used to limit the expected internal bath temperatures to any upper
and lower values. The temperature controller cannot exceed these limits even if
it would be required for reaching the temperature in the external system.
Consequently the external setpoint may thus not be reached.
Sense of a limit setting:
Protects the bath fluid from overheating.
Prevents an undesired alarm shut-down by the excess temperature
protection - >ALARM CODE 14IntMax:< to a value at least 5 °C below the >SafeTemp:< value.
Protects the pump motor from high viscosity of the bath fluid at low
temperatures.
For refrigerated circulators: Freezing protection when using water as bath
fluid.
°C
200
150
Upper band: and Lower band: Band limit
The band limit is active for external control.
internal bath
external system
For the heat-up and cool-down phases
different settings to conform to the
requirements of the particular application
are possible.
Setting range: 0 ... 200 °C
100
75
50
25
AreaUp
AreaDown
10 20 30 40 50 60 10 20 30 40 50 60 10 [min]
During the heat-up phase the difference value always adds to the actual
external temperature. During the cool-down phase, the difference value is
subtracted.
t
Using Upper band and Lower band, the
difference between the temperatures in
the internal bath and the external system
can be limited to any maximum value for
the heat-up or the cool-down phase.
Sense of a band limit:
Ensures gentle heating for the objects requiring temperature application.
Protects glass reactors, for example, from thermal shock.
The IntMax: and IntMin: values are superordinated to this band limit.
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