|
NIST
ITS-90 Low Temperature Calibration Facility
Goals:
Dissemination
of ITS-90 below 83.8 K throughout the nation's low temperature user
community.
Customer Base:
- Cryogenic
Thermometer OEMs
- Cryogenic
Systems and UHV OEMs
- Aerospace
OEMs Liquefied cryogenic fuels and natural gas, suppliers and users
- Superconducting
Magnet OEM's and users Cryo-electronics
- OEM's and
users (e.g. IR detection, SC analog and A/D converters)
- NASA, DOD
and DOE agencies and prime contractor
Range:
- T=83.8 K
to 0.65 K on ITS-90, ( to 0.5 K on NPL-Tx1).
Sensors:
- 13.8 K to
83.8 K -Standard Platinum Resistance Thermometers (SPRTs).
- 0.65 K to
27.1 K (85 K) -Rhodium-Iron Resistance Thermometers (RIRTs).
- 0.5 K to
30 K -Germanium Resistance Thermometers (GRTs).
- 0.5 K to
273 K -Other metallic or semiconductor 4-wire contact thermometers.
- 1.5 K to
273 K -Diode thermometers.
Equipment:
- Recirculating
3He refrigerator,
- Liquid 4He
vented and pumped systems,
- Automatic
ac resistance bridge,
- Precision
dc and low frequency ac automatic test equipment.
Techniques:
SPRTs: 13.8
K to 83.8 K by comparison (ac).
24.5
K to 83.8 K by sealed cell fixed points (ac).
RIRTs: 0.65 K to 27.1 K by comparison (ac).
GRTs : 0.5 K to 30 K by comparison (dc).
Other RTs and diodes: 0.5 K to 273 K by comparison (dc).
Accuracy and Precision:
- Precision
of 0.02 mK @ 4 K,
- Uncertainty
of < 1.0 mK
- Polynomial
fits of < 0.2 mK
Related Work
- Sealed-Cell
Fixed Point Device development for International Comparisons
- SRM development
using capsule SPRTs and Sealed-Cell Fixed Point Devices
- Scale Research
via intercomparisons between 13.8 K and 273.16 K.
- Research
on new sensors and measurement techniques
For more information,
contact Weston Tew at weston.tew@nist.gov
 |
