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Sub Kelvin Temperature Controller 

Our Temperature Controller, product code TC04, provides multi-channel monitoring of high accuracy low temperature thermometers along with remote access and control capability via the Internet.  It is also capable of controlling heaters and is designed to operate with systems operating at millikelvin temperatures.

 Temperature Controller

Specifications

Heater supply

  • Six heaters
  • Relay isolation when off (the heater negative wire is still connected via 10Ohms to cryostat earth)
  • Front panel override and monitoring
  • Open circuit detection
  • Maximum voltage = 25 V
  • Maximum current approx 100 mA

Diode Readouts

  • Eight channels
  • Drive current = 10 uA
  • Maximum voltage sense = 2 V
  • Accuracy = 0.2%
  • Resolution = 0.5 mV via the network interface; 1 mV on the front panel
  • Block disable to short out all diodes (available via Ethernet only)

RTD Readouts

  • Four channels.  Non multiplexed
  • Resistance up to 1 MOhm
  • Constant sinusoidal current drive, 1 nA to 1000 nA
  • Frequency.  Approx 10 Hz to 20 Hz
  • Voltage sense:  100 uV or 1 mV ranges.  In-phase and quadrature measurements.  This ensures that phase changes due to wiring and circuitry can be accommodated
  • Current sense:  1 nA to 1000 nA ranges (matches drive). In-phase measurement only
  • Phase control:  +/- 20 deg
  • Resolution:  As a percentage of the maximum resistance measurable on any decade range, this is 0.025% (network interface) or 0.1% (front panel). For example, at a drive of 1 nA and a maximum voltage of 10 0uV the maximum resistance measurable is 100 kOhm, giving a network interface resolution of 25? and a front panel resolution of 100 kOhm
  • Absolute accuracy of resistance measurement: 0.4% (<100 kOhm) ambient temperature 15 C to 25 C
  • Ground isolated preamplifier on cryostat for each channel

Interface

  • Ethernet. Cat 5e cabling

Control Computer

  • Built-in embedded Java computer
  • Provides control functions and thermometer readout
  • Heaters may be controlled according to a user script, e.g. for recycling a helium sorption fridge
  • RJ45 socket provides direct connection to the ethernet
  • Control and diagnostics are available through a web interface
  • Serves readout data to clients across the network
  • Client for Windows, provide tabular data and logging
  • Open source client libraries for Windows and Linux supplied for application extension 

Edited Dec09