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Model 44C Cryogenic Temperature Controller

Product Folder

Front Panel
Rear Panel

M44front

Highlights of the Model 44C:
Four multipurpose input channels support Diode, Platinum RTD and virtually all cryogenic NTC resistive temperature sensors. Operation from below 20mK to over 1020K with an appropriate sensor. Large, bright and highly configurable display. Step-less Constant-Voltage sensor excitation extends the useful temperature range of resistive temperature sensors. Programmable logic interface controls external equipment. This can provide a complete 'One Box' solution for many systems. Three precision control loops. Loop #1: 50-Watt, four-range. Loop #2: 10-Watt, two-range, Loop #3: 10-Volt		Table control mode automatically switches the loop input sensor to allow smooth, continuous control over a wide range of temperature. Fail-safe cryostat protection features protect user equipment from damage. Unique synchronous filter improves control accuracy and stability in cryocooler based systems. Remote interfaces include 100/10 Ethernet and RS-232. IEEE-488.2 (GPIB) and USB are optional. Remote command language is IEEE SCPI compliant. LabVIEW™ drivers are available for all interfaces.

M44rear

Input Connectors: DIN-6 receptacles provide 4-wire measurement connection plus shield.
Loop #1: 50-Watt heater output. Dual Banana Plug with chassis ground lug.
Loop #2: 10-Watt heater, part of a 10 pin detachable terminal block.
Loop #3: 10-Volt output. Detachable terminal block.
Digital Outputs: Detachable terminal block.
Ethernet: RJ-45 with LAN activity indicator LEDs.
IEEE-488 (GPIB): Option connects to Ethernet port.
RS-232: Null-modem connector (DB-9, pins).
USB: Option connects to RS-232 port.
AC Power: RFI filtered Power Entry Module including fuse drawer and line voltage selector.

General Description

The Model 44C temperature controller is designed for use as a general purpose cryogenic instrument with extended operation into the ultra-low (>1K) temperature range.

Flexible Inputs: The Model 44C has four identical input channels, each of which can be easily configured to operate virtually any type of cryogenic thermometer.

Each input consists of an independent AC resistance bridge that is capable of measurement using the pico-Watt excitation levels that are often required by ultra-low temperature systems.

This resistance bridge is used in a constant-voltage AC mode to provide robust support for the Negative Temperature Coefficient (NTC) sensors including Ruthenium-oxide, Carbon-Glass, Cernox™, Carbon-Ceramic, Germanium and several others.

Positive Temperature Coefficient (PTC) resistor sensors including Platinum and Rhodium-Iron RTDs use the resistance bridge in its constant-current, AC mode. Platinum RTD sensors use a built-in DIN standard calibration curve that has been extended to 14K for cryogenic use. Lower temperature use is possible with custom calibrations.

Silicon Diode sensors are supported over their full temperature range by using the bridge in a DC, constant-current mode.

Programmable Logic Interface: Four optically coupled digital outputs that can be used to control a refrigerator system or other external equipment. This interface is often connected to a Programmable Logic Controller (PLC).

Three Control Loops: Loop #1 is a linear current source that can provide up to 50-Watts. Four full-scale ranges are available down to 50mW.

Loop #2 is a linear heater with two output ranges of 10-Watts and 1.0-Watt full-scale.

Loop #3 is a non-powered voltage output intended to control an external booster power supply. Output is zero to 10-Volts.

Data logging is performed by continuously
recording to an internal 1,000 entry buffer. Data is time
stamped and non-volatile memory is used so that data
will survive a power failure.

Alarms: Visual, remote and audible alarms are available. Each may be independently programmed to assert or clear based on a high or low temperature condition. Latched alarms can be asserted on any alarm condition and will remain asserted until cleared by the user.

Remote Control: Standard remote interfaces include 100/10 Ethernet and RS-232. IEEE-488(GPIB) and USB are optional.

LabView™ drivers are supplied for the Ethernet
TCP/IP, IEEE-488, USB and RS-232 interfaces.

Firmware updates: Full instrument firmware
updates may be installed by using the Ethernet
connection. All updates are free of charge.

Applications

Ultra-Low temperature:

10µV Constant-Voltage excitation offers robust support for Ruthenium-Oxide or Cernox™ sensors to <20mK.
Four input channels. Most refrigerators require at least three.
High precision control loop with PID control that is enhanced for operation below 1.0K.

Cryogen-Free systems:

Four input channels. Cryogen-Free systems often require more than two.
Especially effective in ultra-low temperature cryogen-free systems.

Superconducting Magnets:

Constant-voltage sensor excitation extends the high and low temperature range of sensors normally used in high magnetic fields.
Cryogen-Free magnet systems often require more than two inputs.

General purpose laboratory:

Up to 4 inputs. Each supports virtually every cryogenic temperature sensor offered by every manufacturer.
Constant-Voltage excitation offers the widest possible temperature range for a given sensor.
Dual control loops. Digital Signal Processing techniques extend control loop resolution to provide the best control stability and widest range in the industry.
Ethernet connectivity for ease of remote control. Significant upgrade over IEEE-488 or RS-232 based systems. Native LabView™ support.
Robust cryostat protection controls.
Complete instrument configurations may be saved and instantly restored.

Data Acquisition / Computer control:

Ethernet allows the simple and inexpensive connection of many instruments to a Local Area Network. It is directly supported by all data acquisition software packages including LabView™.
Robust implementation of the IEEE-488.2 SCPI command language facilitates system software development.
Remote command language is identical across the entire product line, therefore ensuring your system software will not become obsolete.

CalGen™ and Cryo-Con™ are registered trademarks of Cryogenic Control Systems, Inc.
All other product and company names are trademarks or trade names of their respective companies.

Tel: (858) 756 3900 Fax: (858) 759 3515
Specifications subject to change without notice. ©Cryogenic Control Systems, Inc. 1998 - 2012.