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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

Johnson Noise Thermometry

Johnson noise thermometry (JNT) is a primary temperature measurement technique based on the fundamental properties of thermal fluctuations in conductors. We
Acoustic Thermometer

Acoustic Thermometry

By measuring the speed of sound in argon gas, we have determined thermodynamic temperature with unprecedented accuracy in the range 0 °C to 552 °C. Our results
photo of membrane in shock tube

Dynamic Pressure

Manufacturing processes by their very nature require a judicious, time-dependent use of pressure and temperature to transform a base material into a valuable

Publications

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

Chemistry from 3D-printed objects

Author(s)
Matthew R. Hartings, Zeeshan Ahmed
3D printing technology has started to take hold as an enabling tool for scientific advancement. Born from the marriage of computer-aided design and additive

Tools and Instruments

Awards

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Highlights

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Contacts

Group Leader

Office Manager