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Metrology

Flow metrology & rheology

News and Updates

schematic of sound-wave transmitter and receiver

Sounding Out a New Way to Measure Gas Flow

Researchers at NIST have developed a new — and sound — way to accurately measure the rate at which gas flows in and out of a vessel. The technique, which uses

Projects and Programs

shaded quasi sphere

Atomic Standard for Pressure

Ongoing
NIST scientists are developing a highly accurate primary standard for pressure in the range 2 MPa to 7 MPa based on fundamental physical properties of helium
The NIST Acoustic Thermometer

Acoustic Techniques in Fluid Metrology

Ongoing
The Fluid Metrology Group leads the world in designing and using gas-filled acoustic resonators for measuring the thermodynamic temperature T, the Boltzmann

Material Qualification

Ongoing
The lack of repeatable process outcomes from additive manufacturing (AM) has been broadly acknowledged as an impediment to widespread implementation. While most

Publications

Gas Flow Standards and Their Uncertainty

Author(s)
John D. Wright, Aaron Johnson, Michael R. Moldover, Shin-ichi Nakao
We review diverse types of gas flow standards that are used to calibrate other gas flow meters. For each type of standard, we describe the principles of its

SerialTrack: ScalE and Rotation Invariant Augmented Lagrangian Particle Tracking

Author(s)
Jin Yang, Yue Yin, Alexander Landauer, Selda Buyukozturk, Jing Zhang, Luke Summey, Alexander McGhee, Matthew Fu, John Dabiri, Christian Franck
We present a new particle tracking algorithm to accurately resolve large deformation and rotational motion fields, which takes advantage of both local and

Tools and Instruments

transient gas flow instruments

Transient Gas Flow Facility

A compressor is used to pressurize up to twenty-five 40 L gas cylinders to 35 MPa. The cylinders can then be used as a source of rapidly changing gas flow by
gas flow standards instrument

Gas Flow Standards

NIST uses pressure, volume, temperature, and time (PVTt) standards to calibrate gas flow meters. PVTt flow standards generate selected, steady gas flows through
wind tunnel instrument

Wind Tunnel

NIST’s wind tunnel can produce air speeds between 0.15 m/s and 40 m/s. The air speed reference is a Laser Doppler Anemometer (LDA) with an uncertainty of 2.5 %

Awards