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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

Events

Projects and Programs

temperature distribution graphs

Understanding Flow Meters

Ongoing
Critical flow venturis (CFVs) are widely used for gas flows of 1 L/min or more, if a significant pressure drop is acceptable. Theoretical discharge coefficient ( Cd): A calculated value of the discharge coefficient allows 0.3% uncertainty from a CFV from a low uncertainty throat diameter measurement
Transient flow facility for vehicle refueling

Transient Flow Facility

Completed
Impact Provide metrological tools and standards supporting the fair trade of hydrogen gas as a vehicle fuel of the future. Objectives Design, construct, and utilize a facility that mimics retail hydrogen fueling station conditions to quantify uncertainties of flow measurement standards and
microfluidic chip

Evaluating Measurement Quality of Microfluidic Cell-based Assays

Completed
Impact and Customers Our work establishes metrics for measurement quality and reproducibility for cell-based assays within microfluidic devices. Many novel microfluidic devices are being created that permit new measurements or enable new biological functions to be tested; however, characterizations

Material Qualification

Ongoing
Objective 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

Publications

Calibrating laser Doppler anemometers utilizing an optical chopper

Author(s)
Christopher Crowley, Iosif Isaakovich Shinder, Michael R. Moldover, Joey Boyd, James Filla, Aaron Johnson
Laser Doppler anemometers (LDAs) use scattered light to determine velocity components of a flowing fluid. The operating principal of LDAs is simple conceptually

Tools and Instruments

Gas Flow Standards

Summary NIST's gas flow meter calibrations support a wide range of industries that require low-uncertainty, SI-traceable measurements. These industries include
15 kg/s liquid flow standard

Liquid Flow Standards

Summary The Fluid Metrology Group has a dynamic, gravimetric liquid flow standard spanning the flow range 0.2 L/s to 15 L/s with uncertainty less than 0.03 % at
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