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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

Tracking Lab-Grown Tissue With Light

Someday, doctors would like to grow limbs and other body tissue for soldiers who have lost arms in battle, children who need a new heart or liver, and many

Projects and Programs

Humidity

The NIST Thermodynamic Metrology Group maintains and develops national standards of humidity (in the range 1 nmol/mol to 0.6 mol/mol of water concentration)

Hybrid Humidity Generator

NIST's new primary standard humidity generator, the Hybrid Humidity Generator (HHG), replaces the NIST 2-Pressure Humidity Generator, Mark 2 (2-P). The HHG

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

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

Piston gauges and pressure transducers

Piston gauges are used to calibrate customer piston gauges and pressure sensing devices. Piston gauges are calibrated via a direct comparison to another piston

Low Pressure Gauges

NIST has developed best-in-the-world primary standard pressure measurement capabilities for pressures spanning the range of 0.01 Pa to 360 kPa through the

Awards

Contacts

Group Leader

Office Manager