Thermo Scientific F30400, Installation And Operation Manual

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8 Segment & 4x16 Segment Programmable Models w/OTP
Tuning your Furnace
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Large Tabletop Muffle Thermo Scientific
Tuning your Furnace
The purpose of tuning your furnace is to match the characteristics of your controller to the
characteristics of the process being controlled. Good control is evidenced by: stable, straight-line
control of the setpoint temperature with no fluctuations; No overshoot or undershoot of the setpoint
temperature; rapid restoration of the setpoint temperature when external disturbances cause deviations
from the setpoint.
This controller has automatic tuning features which install optimum tuning parameters to give the best
temperature accuracy. No manual loading of tuning parameters is needed. We recommend that you
tune the furnace to your specific application to obtain the best results. To provide the best temperature
accuracy possible, use these features when you install your furnace and whenever you change your
application or procedure.
Tuning Error
The display will flash “tu.ER” if an error occurs during tuning. To clear the error and restart tuning,
simultaneously press the PAGE and SCROLL buttons and follow the steps outlined in “Autotuning.”
The display will flash “tu.ER” if an error occurs during tuning. To clear the error and
restart tuning, simultaneously press the PAGE and SCROLL buttons and follow the
steps outlined in “Autotuning.”
To stop the tuning function, simultaneously press the PAGE and SCROLL buttons.
Gain Scheduling
G.SP: Gain Scheduling
Gain scheduling is the automatic transfer of control between two sets of PID values. The 2416
controller does this at a presettable process value. Gain scheduling is used for difficult control processes
which show large changes in their response time or sensitivity at high or low temperatures, or when
heating or cooling.
The G.SP gain schedule setpoint is factory set at 700° C. The G.SP must be adjusted to 200°C from
the desired setpoint temperature when tuning.
Setting the Transfer Point
If gain scheduling has been enabled, “G.SP will appear at the top of the PID list. This sets the value at
which the transfer will occur. When the process value is below this level, PID1 will be active and when
it is above, Pid2 will be active. Set a value between the control regions that show the greatest change to
achieve the best point of transfer.