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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

NIST researchers measuring a flow profile

Smoke Stack Flow Measurement

Ongoing
The Fluid Metrology Group is using its smoke stack simulator (See Fig. 1.) and field tests in operating smoke stacks to critically test conventional and improved ways of measuring the flow of stack gases. In the NIST stack simulator, the inlet cone and reference (upstream) section of the simulator
two-capillary viscometer

Gas properties for flow metering

Ongoing
NIST has two on-line databases that include accurate gas viscosity values: SEMIPROP - NIST Standard Reference Database 134 - for selected semiconductor process gases NIST Chemistry WebBook - for heat transfer fluids, components of air, components of natural gas [Note: as of February 2014, the NIST
MGI-Logo

Modeling Dispersion Rheology for Non-Spherical Particles

Completed
The goal of this MGI project is to establish an interactive database, generated by sophisticated modeling, such as dissipative particle dynamics and smooth particle hydrodynamics, to compute the rheological properties of polymer composites, where interaction among inclusions, inclusion particle

Precursor Material Qualification

Completed
To develop, utilize, and analyze methods of characterizing the precursor materials in additive manufacturing in both virgin and recycled states with the goal of advancing measurement science to benefit the AM community. The components of principal interest will include the rheological, size

Publications

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
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