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Physical Measurement Laboratory /Sensor Science Division

Thermodynamic Metrology Group

The Thermodynamic Metrology Group realizes, maintains, and disseminates the national measurement standards for temperature, humidity, pressure, vacuum, and leaks.

The group mission is to advance the state of the art in measurement of thermodynamic quantities. We have active efforts in optics, nano-photonics, and quantum-based metrology along with traditional precision measurements to advance U.S. industry. We collaborate nationally and internationally, and engage in metrology education and outreach.

News and Updates

Projects and Programs

background molecule

Cold Core Technology Platform

We are building a cold-atom based sensor program that represents a new approach to metrology—to establish a set of chip-scale tools that enable real-world use

Thermometry

The NIST Thermodynamic Metrology Group maintains and develops national standards of temperature (in the range 0.65 K to 1235 K), and supports calibration of all

Pressure

The NIST Thermodynamic Metrology Group (TMG) provides critical research into pressure measurement capabilities improving uncertainties in user facilities and
Photonic thermometer packages

Photonic Thermometry

Resistance thermometry, a time-tested method for taking temperature measurement, relies on taking accurate temperature-dependent resistance measurement of a

Publications

On-chip Silicon Photonics Radiation Sensors

Author(s)
Nikolai N. Klimov, Zeeshan Ahmed, Lonnie T. Cumberland, Ileana M. Pazos, Ronald E. Tosh, Ryan P. Fitzgerald
We have examined the impact of cobalt-60-ray radiation up to 1 megagray (MGy) absorbed dose on silicon photonic devices. We do not find any systematic impact

A photonic pH sensor based on photothermal spectroscopy

Author(s)
Zeeshan Ahmed, Nathan J. Castro, Matthew R. Hartings
Although the determination of pH is a standard laboratory measurement, new techniques capable of measuring pH are being developed to facilitate modern

Johnson Noise Thermometry

Author(s)
Weston L. Tew, Jifeng Qu, K L. Zhou, Samuel P. Benz, Horst Rogalla, David R. White
Johnson noise thermometers infer thermodynamic temperature from measurements of the thermally-induced current fluctuations that occur in all electrical

Tools and Instruments

Vacuum Gauges

Most calibrations of vacuum gauges are based on a known gas flow rate that is generated by one of two flow meters that operate at constant pressure. The "piston

Leak Artifacts

Leak artifacts are calibrated in the range 1 x 10-6 to 1 x 10-13 mol/s (2 x 10-2 to 2 x 10-9 std. cm3/s at 0 °C). The calibration can be performed directly

Awards

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Highlights

Related Links

Contacts

Group Leader

Office Manager