SRS Labs CTC100, Руководство пользователя

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Introduction 1
CTC100 Programmable Temperature Controller
The CTC100 is a high-performance cryogenic temperature controller that can monitor and
control temperatures with millikelvin resolution. Its features include:
4 tem pera ture sen sor inp uts
Eac RTDs, thermistors, and diodes.
Each temperature input channel has its own 24-bit ADC with ten input ranges that can be
automatically or manually selected. By default each sensor is read 10 times per second, but the rate
can be set as low as 1 Hz or as high as the line frequency (50 or 60 Hz).
Each input has an independent excitation current source. The excitation current is automatically
selected based on the input range. The direction in which the excitation current flows through the
sensor can be reversed to detect EMF errors, and the CTC100 can automatically reverse the
current direction at every ADC reading and display the average of forward and reverse current
readings.
Standard calibration curves for a variety of sensors are included, and custom calibration curves of
up to 400 points each can be entered by saving a text file on a USB memory stick and then plugging
the memory stick into the CTC100. Calibrations can be adjusted by entering an offset and gain
from the front panel.
Each sensor input has high and low level or rate-of-change alarms. Alarms can be latching or non-
latching and when triggered, can shut off a heater output, trip a relay, and/or create one of four
alarm sounds.
Sensor inputs can be lowpass-filtered to reduce noise and/or differenced with another channel.
The rate of change of sensor inputs can be calculated.
-amplified
sensor signals.
2 powered a nd 4 unpowered hea ter outputs
The CTC100 has two heater outputs, each capable of delivering up to 100W of power to a 25
ohm heater. In addition, four unpowered voltage I/O channels can be used to drive heaters with
the help of an external amplifier.
U p to 6 feedba ck control loops
Each heater output can be controlled by a PID feedback loop that continually adjusts the heater
power to keep a sensor at a constant temperature.
Feedback time constants can be adjusted between about 200 ms and 10 hours and can be tuned
manually or automatically. Depending on the amount of overshoot that is acceptable, aggressive,
moderate, or conservative tuning goals can be selected.
Up to ten sets of feedback parameters can be stored for each channel; each set of parameters can
be assigned a temperature range and automatically recalled when the temperature falls within that
range. The temperature sensor used for the feedback loop can also be selected based on the
temperature.
Setpoints can be ramped at a fixed rate or, with a user program, set from an analog input.
Feedforward and cascade feedback are supported.