Status: Need is Closed

Low-cost solution for cryogenic temperature measurement

Request Number

Point of Contact
Need was closed on
Oct 6, 2018

A reliable and low-cost solution is required for measuring the temperature of components within a:

  • Gaseous and liquid environment within a cryogenic helium vessel
  • Vacuum vessel between the temperature range of 300-3K
  • Magnetic fields up to 8T


A low-cost solution is required for measuring temperatures within the range 3-300K, with an accuracy of:

  • 0.2K between 3K and 6.5K
  • 1.0K between 6.5K and 20K
  • 5.0K between 20K and 50K
  • 20.0K between 50K and 300k


It may be acceptable for a solution to be proposed that can cover all the ranges of temperature however different solutions may also be considered for individual ranges if optimised solutions can be offered for some or all of the ranges.


Our current solution to measuring the temperatures within the environments described above has relied upon the use of Carbon Ceramic Resistors  (CCR) mounted directly to the components with the resistor attached to an electrical loom that can be accessed outside of the cryogenic/vacuum vessel. The reliability of sourcing these resistors has become increasingly more difficult and the consistency of their performance during calibration has resulted in a large proportion of them being unfit for use in the application required. We are therefore interested in finding an alternative solution that is both reliable, easily sourced and at a total-cost that is comparable to the CCR. Prior to release for use in production each CCR is required to be calibrated at 3 temperature points: room; 77K and 4K. This calibration is a large percentage of the overall cost with the final price for the calibrated component being ca. £30.

Key success Criteria

The solution shall be capable of:

  • Measuring temperatures within the range 3-300k.
  • Reliably measuring with the accuracy:
    • 0.2K between 3K and 6.5K
    • 1.0K between 6.5K and 20K
    • 5.0K between 20K and 50K
    • 20.0K between 50K and 300K
  • Working within both a vacuum and 4K gaseous and liquid environment.
  • Working within a magnetic field of up to 8.0T.
  • Capable of being easily attached to both a metallic and non-metallic surface.
  • Capable of generating an output that can be measured outside of the 4-6mm thick stainless steel housing vessel e.g. current solution is wired but wireless options would be considered.
  • Low power dissipation in the temperature sensor during operation,  <0.1mW
  • High reliability. Once fitted the solution is not capable of being accessed or replaced and therefore the reliability of the component is essential (~15 years). The sensor must be able to withstand repeated thermal cycling from 300K down to the lowest operating temperature.
  • Component performance to be stable across manufacturing batches to limit calibration efforts.
  • Proposed solution to be less than the current price
  • If the proposed temperature sensor solution includes measurement wires, these must be made of low thermal conductivity materials e.g. Constantan.
  • Small geometrical footprint (ca. <2cm3)excluding wiring if necessary
  • RoHS compliant.
  • Globally available. Annual requirements would be in the region of 7000-10000 units per annum.
Possible Approaches

The current solution (CCR) is both compact and capable of being attached to the required surfaces of the components to be measured which include aluminium alloys and epoxy resin composites, any alternative solution should also be capable of this either via adhesive bonding or via a thermally conductive mechanical method. Similar sensors are available such as a RuO2 thick film SMD resistors, however, although these have good resolution at the low temperatures in the required range this reduces at around 50K. This does not rule out the use of this option but will not fulfil all the necessary requirements of measurement throughout the full temperature range.

Approaches not of Interest

All options that align to the key success criteria shall be considered.

Due Date
Sep 30, 2018
Items to be submitted

Items to be submitted in responses:

Solutions to this problem should describe in detail the following aspects:

  • Capability of the solution to achieve the required resolution
  • Requirement to calibrate solution either individually or via batch calibration (Can a calibration certificate be supplied with the component?)
  • Geometric description of the solution
  • Method of attaching the solution to the component.
  • Availability of the solution
  • Conformance to RoHS requirements
  • Price estimation based on all elements below the current price paid e.g. component and calibration)
  • Timeline to supply a development sample, (if not already a productionized solution).
Gallery Moderator(s)
Stephen Clulow
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