SRS Labs CTC100, Руководство пользователя

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Operation 39
CTC100 Programmable Temperature Controller
Suggestions for best tuning results
separate graphs. Make sure that you can see the temperature begin to rise or fall after the
heater output changes.
If tuning fails, let the temperature stabilize and try increasing the step Y or lag before
attempting to tune again. You may also need to increase the lowpass filter time constant.
The temperature must be stable when tuning is started. Either the feedback must be running
and stabilized at the setpoint, or the heater must be off and the temperature stabilized at the
ambient temperature.
Set the lowpass filter on the input (temperature) channel to a value just below the expected
response time of the system. The step response tuner in particular requires adequate lowpass
filtering to produce accurate results.
process.
Since the ideal feedback parameters usually vary with temperature, run the tuning algorithm
at about the temperature at which the feedback will be used. If the system has never been
tuned before you may need to tune at room temperature, then let the feedback bring the
system to its working temperature, and re-tune at the working temperature.
The autotuning algorithm assumes that the temperature is a linear function of heater power.
by the algorithm may not be
perfectly accurate and may need to be manually adjusted.
U sing alarms w ith P ID feedback loops
By default, the PID heater output is frozen whenever the sensor becomes disconnected or goes
out of range. In some cases this can lead to uncontrolled heating or cooling of the sample. For
example, if the feedback setpoint is set to 200 degrees but the sensor can only measure
temperatures as high as 100 degrees, the CTC100 will continue heating the sample indefinitely.
Each input channel has an alarm that can be used to prevent such runaway heating. When
properly configured, alarms set the heater output to zero whenever the sensor is disconnected, out
of range, or the temperature exceeds limits that you specify. Alarms should be set up whenever the
heater is capable of providing enough heat to damage your system.