Cryogenic Temperature Sensors
Our partnerLake Shore Cryotronics

Cryogenic Temperature Sensors

From Lake Shore Cryotronics

The choice of the right temperature sensor is essential for an accurate and realistic determination of low temperatures in a cryostat. For this purpose, each sensor can be attributed with an individual set of properties, like temperature range, accuracy and resolution, magnetic resilience, radiation resilience and package options. We are offering Cernox, Silicon Diodes, Gallium Aluminum Arsenide (GaAlAs) Diodes, Germanium, ROx, Platinum, Capacitance and Thermocouple temperature sensors. Depending on the sensor type, different packages are available, like specially designed, bare chips, bolt-down and embedded packages.

Features
  • 0.01K to 1543 K temperature range
  • Excellent magnetic field performance
  • Good Radiation resistance
  • High vacuum compatible

Further information

  Temperature rangeStandard curveBelow 1 KCan be used in radiationPerformance in magnetic field
Negative Temperature Coefficent RTDs
Cernox®0.10 K to 420 K Excellent above 1 K
Germanium0.05 K to 100 K Not recommended
Ultra-low temperature Rox™<0.01 K to 40 KGood below 1 K*
Interchangeable Rox™0.05 K to 40 KGood below 1 K*
Diodes
Silicon1.4 K to 500 K  Fair above 60 K
GaAlAs 1.4 K to 500 K   Fair
Positive Temperature Coefficient RTDs
Platinum14 K to 873 K Fair above 30 K
Other
Capacitance1.4 K to 290 K   Excellent
Thermocouple Wire1.2 K to 1543 K  Fair
Specialty
HR Series20 K to 420 K  

Excellent

Specification

Cernox

  • Thin film resistance cryogenic temperature sensor
  • Non-magnetic packages

Germanium

  • Temporarily unavailable – please consider Cernox as an alternative.
  • resistance temperature sensors
  • “Secondary Standard Thermometer”
  • High sensitivity at submillikelvin temperatures

Ultra-low temperature Rox™

  • calibrations down to 10 mK available
  • Dilution refrigerator applications
  • Optical shielding improves sensor thermal stability

Interchangeable Rox™

  • RX-102A, RX202A and RX-103A
  • Standard curve interchangeable
  • Good radiation resistance
  • Low magnetic field-induced errors

Silicon Diodes

  • DT-670-SD, DT-670E-BR and DT-621-HR
  • Best accuracy across the widest useful temperature range of any silicon diode
  • minimized sensor self-heating
  • Conformance to standard Curve DT-670 temperature response curve

GaAlAs Diodes

  • Monotonic temperature response
  • Excellent sensitivity (dV/dT) at temperatures below 50 K

Platinum Positive Temperature Coefficient RTDs

  • Conforms to IEC 751 standards down to 70 K
  • High reproducibility: ±5 mK at 77 K
  • SoftCal™ calibration available
  • Non-magnetic packages available (all PT-102 and PT-103 variants)

Capacitance

  • Capable of mK control stability in the presence of strong magnetic fields
  • Monotonic in C versus T to nearly room temperature

Thermocouple Wire

  • Type E (Chromel-Constantan)
  • Type K (Chromel-Alumel)

HR Series

  • 15 years of full material traceability
  • Resistance and sensitivity data
  • Gain confidence from our test protocol

Applications

Temperature is a thermodynamic quantity that describes the state of a body. To measure this state, a second body can be brought into contact with the first. This causes the temperature in both bodies to equalize after a certain period.

Thermodynamically, the difference between the temperature of two bodies can always be determined. From this the temperature scale was developed, which refers to the absolute zero point. In the SI system this is the Kelvin scale, which is measured in Kelvin [K] (see box for further scales). Fixed points of this scale are so-called triple points. At these points an atomic species or a compound like water (H2O) is simultaneously present in all three aggregate states, i.e. solid, liquid and gaseous. This is the case for water at 273.16 K. This point is assigned to exactly one pressure and one temperature. The boiling temperature of water (temperature at the transition from liquid to gaseous) varies depending on the pressure and is therefore not clearly defined.

Temperature Conversion Formulas

  • degrees Celsius T[°C] = T[K]-273.15
  • degrees Fahrenheit T[°F] = T[°C] x 1.8+32
  • Degree Rankine T[°R] = T[K] x 1.8
  • Degree Réaumur T[°Ré] = (T[K] - 273.15) x 0.8

Thermometers are used to measure the temperature. These are measuring instruments whose measurable data output changes with temperature in a reproducible manner. In general, a distinction is made between primary and secondary thermometers. A primary thermometer is characterized by the fact that its dependence on temperature can be described without unknown and temperature-dependent variables. For example, gas thermometers, acoustic thermometers, noise thermometers and total radiation pyrometers. A secondary thermometer outputs a value that must be calibrated using fixed temperature points. The Platinum RTD (Resistance Temperature Detector) is an example of a secondary thermometer and is based on the change in the electrical resistance of a platinum wire as a function of temperature.

Since primary thermometers are large, slow and expensive, secondary thermometers are used almost exclusively in practice. The secondary thermometers are calibrated using international standards and fixed temperature points. These are defined in IST-90 (International Temperature Scale of 1990) and PLTS-2000 (Provisional Low Temperature Scale of 2000).

Responsible for defining the temperature scale are government authorities such as NIST (National Institute of Standards and Technology), NPL (National Physical Laboratory) and PTB (Physikalisch-Technische Bundesanstalt).

For temperature sensors with extremely reproducible manufacturing processes, tolerance curves are created that indicate how close the temperature curve obtained is to the calibration standard. Examples are Si diodes and platinum thermometers, where it is possible to exchange individual sensors of the same design and still achieve an accurate measurement of the temperature. The degree of accuracy is determined by tolerance bands.

The different temperature sensors (silicon diodes, platinum RTDs and NTC temperature sensors) can be read out by means of a temperature monitor. The temperature controllers go one step further, where the temperature is measured by means of a temperature sensor and then actively set to the desired value by means of an additional heater.

High end applications for the HR series are among others, space telescopes, supercolliders, fusion reactors, research satellites and maglev locomotives.

Downloads

Termperature sensor selection guide
Termperature sensor selection guide

Videos

Contact

Dr. Simone Paziani
Dr. Simone Paziani

Contact

Quantum Design s.r.l.

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00143 Roma
Italy

Phone:+39 06 5004204
Fax:+39 06 5010389
E-mail:italy@qd-europe.com
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Simone PazianiProduct Manager
+39 06 5004204
paziani@qd-europe.com