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Calibration of Cryogenic Resistance Thermometers

The NIST Low Temperature Calibration Facility (LTCF) can accommodate most capsule and miniature type resistance thermometers suitable for use in vacuum within the range 0.65 K to 83.8 K, with special tests possible as high as 165 K. Calibrations of cryogenic resistance thermometers at NIST are performed by comparison to standard thermometers on the International Temperature Scale of 1990 (ITS-90) for the following thermometers:

  • capsule standard platinum resistance thermometers (SPRTs)
  • rhodium-iron
  • germanium
  • platinum cobalt
  • zirconium nitride, ruthenia

Additional special tests are available for non-standard cryogenic thermometers.

The Standard Platinum Resistance Thermometer Calibration Laboratory (SPRTL) calibrates thermometers from 84 K to 1235 K (Ar TP to Ag FP). Information for these calibrations are found on the ITS-90 Defining Artifacts webpage.

How to Arrange a Calibration

  1. Contact the staff member in charge of the calibration service for your artifact with any technical or calibration cost questions.
  2. Calibrations are performed on a first come first serve basis.
  3. Ship your artifact with a copy of the purchase order. Use a sturdy box in which we can return the calibrated instrument.
  4. The purchase order may be sent to contact by e-mail, fax, or mail. Please include the following information:
  • service ID for the calibration
  • model and serial number of your artifact
  • customer contact name, address, phone, and e-mail
  • return shipping method (e.g., shipping account number)  

For contact information, shipping address, or cost of calibration, see Resistance Thermometry.


Calibration Measurement Uncertainties


ITS-90 Defining Fixed-Points for Capsule SPRTs

Fixed-Point Cell

U (k=2), mK

e-H2 TP

0.41

e-H2 VP

0.89

e-H2-VP

0.23

Ne TP

0.40

O2 TP

0.19

Ar TP

0.32

Hg TP

0.49

TPW

0.20



ITS-90 Subrange for Capsule SPRTs

Temperature
Range, K

Maximum
U (k=2), mK† 

13.8033 to 273.16

1.36

† The ITS-90 temperature subrange uncertainties include the propagated fixed-point uncertainties and the contribution from non-uniqueness types I and III.



Rhodium-Iron Resistance Thermometers

Temperature
Range, K

Maximum
U (k=2), mK

0.65 to 2

0.50

2 to 5

0.32

5 to 9

0.23

9 to 14

0.30

14 to 17

0.34

17 to 20.5

0.40

20.5 to 24.5

0.50

24.5 to 54

0.58

54 to 84

0.40