Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Flow metrology & rheology

News and Updates

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

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

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

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 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

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

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