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Search Publications by: John D. Wright (Assoc)

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Displaying 1 - 25 of 67

Non-nulling Protocols for Fast, Accurate, 3-D Velocity Measurements in Stacks

July 28, 2023
Author(s)
Iosif Isaakovich Shinder, Aaron Johnson, James Filla, Vladimir B. Khromchenko, Michael R. Moldover, Joey Boyd, John D. Wright, John R. Stoup
We present protocols for making fast, accurate, 3-D velocity measurements in the stacks of coal-fired power plants. The measurements are traceable to internationally-recognized standards; therefore, they provide a rigorous basis for measuring and/or

Gas Flow Standards and Their Uncertainty

December 12, 2022
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 operation and at least one hardware example. We identify the practical limits of the example's

Evaluating Inter-Laboratory Comparison Data

November 3, 2022
Author(s)
Enrico Frahm, John D. Wright
The primary purpose of inter-laboratory comparisons is to demonstrate that the uncertainty specifications of the calibration measurement capabilities of the participating laboratories are correct. The most common criterion for assessing a participating

Disinfection of Respirators with Ultraviolet Radiation

March 25, 2022
Author(s)
Dianne L. Poster, Matthew Hardwick, C Cameron Miller, Michael A. Riley, W. W. Shanaka I. Rodrigo, Andras E. Vladar, John D. Wright, Christopher D. Zangmeister, Clarence Zarobila, Jeremy Starkweather, John Wynne, Jason Yilzarde
Data for interpreting virus inactivation on N95 face filtering respirators (FFRs) by ultraviolet (UV) radiation are important in developing UV strategies for N95 FFR disinfection and reuse for any situation, whether it be everyday practices, contingency

Thermal Boundary Layers in Critical Flow Venturis

July 30, 2021
Author(s)
John D. Wright, Aaron Johnson, Michael R. Moldover, Woong Kang, Liang Zhang, Bodo Mickan
We improve the usefulness of small (diameter 10 mm) critical flow venturis (CFVs) as transfer standards for gas flow by measuring and explaining how their discharge coefficients depend on the temperature T of their environment. At Reynolds numbers Re 2.5

Comparison Demonstrates Factor of Three Improvement in Gas Flow Measurements

July 21, 2021
Author(s)
John D. Wright, Gina Kline, Kevin John, Brian Novitsky, Jason Bellavance, Kevin SHufelt, Bradley Nease, Miles Owen, Joseph Allen, Casey Rombouts, William Gause, John Cuccio
A comparison of seven gas flow calibration laboratories piloted by NIST used four laminar flow meters as the transfer standards for nine nitrogen gas flows ranging from 1 sccm to 10 slm. The comparison reference value was calculated from the uncertainty

LIQUID FLOW METER CALIBRATIONS WITH NIST's 15 kg/s WATER FLOW STANDARD

June 15, 2021
Author(s)
Jodie Gail Pope, Aaron Johnson, James Filla, Vern E. Bean, Michael R. Moldover, Joey Boyd, Christopher J. Crowley, Iosif Isaakovich Shinder, Keith A. Gillis, John D. Wright
We describe the 15 kg/s water flow calibration standard operated by the Fluid Metrology Group of the National Institute of Standards and Technology (NIST) to calibrate liquid flow meters for customers. The 15 kg/s standard is a dynamic, gravimetric, liquid

Automated Substitution Weighing Apparatus for Liquid Volume Measurement

June 26, 2019
Author(s)
John D. Wright, Sherry D. Sheckels, Joey T. Boyd
The custody transfer of petroleum worth $1 × 10 12 / year is traced to the volume delivered from provers and liquid test measures. Mistakes as small as 0.02 % in a custody meter calibration can lead to multi-million dollar corrections in bills. NIST

Reproducibility of Liquid Micro-Flow Measurements

June 26, 2019
Author(s)
John D. Wright, James W. Schmidt
New applications in biology, medicine, and manufacturing require reliable measurements of liquid flows smaller than 100 υL/min. NIST addressed this requirement by improving the reliability and ease of use of NIST’s Dynamic Gravimetric Micro-Flow Standard

Improving Measurement for Smokestack Emissions - Workshop Summary

September 21, 2018
Author(s)
Rodney A. Bryant, Aaron N. Johnson, John D. Wright, Tamae M. Wong, James R. Whetstone, Michael R. Moldover, Iosif I. Shinder, Scott Swiggard, Chris Gunning, David Elam, Tom Martz, Eric Harman, David Nuckols, Liang Zhang, Woong Kang, Salvator Vigil
The complex flow conditions inherent in power plant smokestacks make accurate flow measurements challenging, which in turn limits the accuracy of hazardous emissions measurements. While stack composition measurements are assessed daily via comparison to a

Errors in Rate of Rise Gas Flow Measurements from Flow Work

March 20, 2018
Author(s)
John D. Wright, Aaron Johnson, Gina Kline, Michael R. Moldover
The rate of rise (RoR) method measures the time rate of change of the mass of gas in a collection volume as it is filled via a flow meter under test. The mass of gas is calculated from time-stamped pressure and temperature data gathered from the known

Microparticle tracking velocimetry as a tool for microfluidic flow measurements

June 7, 2017
Author(s)
Paul NMN Salipante, Steven D Hudson, James W. Schmidt, John D. Wright
The accurate measurement of flows in microfluidic channels is important for commercial and research applications. We compare the accuracy of flow measurement techniques over a wide range flows. Flow measurements made using holographic microparticle

Transfer Standard Uncertainty Can Cause Inconclusive Inter-Laboratory Comparisons

October 7, 2016
Author(s)
John D. Wright, Blaza Toman, Bodo Mickan, Gerd Wubbeler, Olha Bodnar, Clemens Elster
Inter-laboratory comparisons use the best available transfer standards to check the participants’ uncertainty analyses, identify underestimated uncertainty claims or unknown measurement biases, and improve the global measurement system. For some measurands

Hydrogen Field Test Standard: Laboratory and Field Performance

November 10, 2015
Author(s)
Jodie G. Pope, John D. Wright
The National Institute of Standards and Technology (NIST) developed a prototype field test standard (FTS) that incorporates three test methods that could be used by state weights and measures inspectors to periodically test retail hydrogen dispensers, much

Micro-Flow Calibration Facility at NIST

April 15, 2015
Author(s)
James W. Schmidt, John D. Wright
The Fluid Metrology Group (FMG) at NIST is developing a primary, dynamic gravimetric liquid flow standard for use in the range 1 mL/min to 100 nL/min (and eventually lower). An elevated reservoir of water with a pressure head of a few centimeters provides

Pass / Fail / Inconclusive Criteria for Inter-Laboratory Comparisons

April 14, 2015
Author(s)
Blaza Toman, Bodo Mickan, Gerd Wubbeler, Olha Bodnar, Clemens Elster, John D. Wright
Inter-laboratory comparisons use the best available transfer standards to check participants uncertainty analyses, identify underestimated uncertainty claims or measurement errors, and improve the global measurement system. For some measurands (e.g. flow)

Thermal Effects on Critical Flow Venturis

April 14, 2015
Author(s)
John D. Wright, Aaron N. Johnson, Michael R. Moldover, Woong Kang, Liang Zhang
Critical flow venturis (CFVs) are widely used as working and transfer standards for gas flow measurement because of their long-term calibration stability (5 (e.g., a 2 mm throat diameter flowing air at 1 MPa), CFVs exhibit sensitivity to the environmental

Microwave Determination of the Volume of a Pressure Vessel

December 9, 2014
Author(s)
Michael R. Moldover, James W. Schmidt, Keith A. Gillis, James B. Mehl, John D. Wright
Using microwave techniques that are scalable to very large volumes, we measured the interior volume of a 0.3 m 3, commercially-manufactured, pressure vessel with an uncertainty of 0.05 %, as confirmed by independent, more-accurate, gas-expansion

Hydrogen Field Test Standard: Laboratory Performance

April 14, 2014
Author(s)
Jodie G. Pope, John D. Wright
NIST developed a prototype field test standard (FTS) that incorporates three test methods that could be used by state weights and measures inspectors to periodically test retail hydrogen dispensers, much as gasoline dispensers are tested today. The three