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Search Publications by: Aaron Johnson (Fed)

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Displaying 1 - 25 of 53

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

Facility for calibrating anemometers as a function of air velocity vector and turbulence

July 19, 2021
Author(s)
Iosif Isaakovich Shinder, Michael R. Moldover, James Filla, Aaron Johnson, Vladimir B. Khromchenko
NIST calibrates anemometers as a function of airspeed vector and turbulence intensity (Tu). The vector capability (sometimes called '3D') is particularly important for calibrating multi-hole differential-pressure probes that are often used to quantify

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

Blow-Down Calibration of a Large Ultrasonic Flow Meter

April 21, 2021
Author(s)
Aaron Johnson, Eric Harman, Joey Boyd
Oil and gas production industries use large (diameter > 0.8 m) ultrasonic flow meters (USMs) to measure exhaust gas from flare stacks, emissions from smokestacks, flow of natural gas, etc. Since most flow laboratories do not have compressors with

Faster, More Accurate, Stack-Flow Measurements

February 25, 2020
Author(s)
Aaron N. Johnson, Iosif I. Shinder, Bernard J. Filla, Joey T. Boyd, Rodney A. Bryant, Michael R. Moldover, Thomaa D. Martz, Matthew Gentry
Exhaust flows from coal-fired electricity-generating-plants are determined by measuring the flue gas velocity at prescribed points in the stack cross section. These velocity measurements are made using EPA-approved differential pressure probes such as the

Non Nulling Measurements of Flue Gas Flows in a Coal-Fired Power Plant Stack

June 28, 2019
Author(s)
Aaron N. Johnson, Iosif I. Shinder, Bernard J. Filla, Joey T. Boyd, Rodney A. Bryant, Michael R. Moldover
Exhaust flows from coal-fired stacks are determined by measuring the flue gas velocity at prescribed points in the stack cross section. During the last 30+ years these velocity measurements have been made predominantly using S-type pitot probes. These

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

Characterization of Five-Hole Probes used for Flow Measurement in Stack Emission Testing

May 16, 2018
Author(s)
Iosif Isaakovich Shinder, Aaron Johnson, Michael R. Moldover, James Filla, Vladimir Khromchenko
We report progress towards the goal of reducing the errors in industrial smokestack flow measurements to 1 % by replacing S-probes with calibrated 3-D probes (i.e., probes that measure 3 components of velocity). NIST calibrated a commercially-manufactured

Progress Towards Accurate Monitoring of Flue Gas Emissions

May 16, 2018
Author(s)
Aaron Johnson, Iosif Isaakovich Shinder, Michael R. Moldover, Joey Boyd, James Filla
The amounts of CO2 and other pollutants emitted by a coal-fired power plant are measured using a continuous emissions monitoring system (CEMS) permanently installed in the exhaust smokestack. The pollutant flux is the product of the pollutant's

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

NIST Programs to Advance Accurate, Internationally-Recognized Stack Emissions Measurements

September 15, 2016
Author(s)
Aaron Johnson, Iosif Isaakovich Shinder, Rodney A. Bryant, JohnPaul R. Abbott, Keith A. Gillis, Joey Boyd, James Filla, Michael R. Moldover
Accurate flow measurements are essential to quantify the amount of greenhouse gases (GHGs) and other pollutants emitted from power plant stacks. Although protocols have been developed, the uncertainty of stack flow measurements has not been documented. 

Measurement Challenges and Metrology for Monitoring CO2 Emissions from Smokestacks – Workshop Summary

January 20, 2016
Author(s)
Aaron N. Johnson, Rodney A. Bryant, Tamae M. Wong, James R. Whetstone, Eric Harman, Woong Kang, Keith A. Gillis, Hsin-Hung Lee, Iosif I. Shinder, Liang Zhang
On April 20-21, 2015, NIST hosted a workshop that, through measurement science, enabled the owners of stationary sources (primarily the electric power industry) and their regulatory agencies (federal and state) to better characterize greenhouse gas (GHG)

Design and Capabilities of NISTs Scale-Model Smokestack Simulator (SMSS)

April 17, 2015
Author(s)
Aaron N. Johnson, Joey T. Boyd, Eric Harman, Mohammad M. Khalil, Jacob E. Ricker, Christopher J. Crowley, Rodney A. Bryant, Iosif I. Shinder
The amount of CO 2 emitted from a coal-fired power plant (CFPP) is measured by continuous emissions monitoring systems (CEMS) permanently installed in the exhaust smokestack. Both the CO 2 concentration and the bulk flow are continuously measured by CEMS

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

NIST's Fully Dynamic Gravimetric Liquid Flowmeter Standard.

April 13, 2015
Author(s)
Jodie G. Pope, Aaron N. Johnson, Bernard J. Filla, Joey T. Boyd, Vern E. Bean, Christopher J. Crowley
We describe a new dynamic, gravimetric, liquid flow standard (LFS) that determines flow by measuring the rate of change of the liquid mass accumulating in a collection tank. The LFS is a fully- automated,15 kg/s system that uses a proportional–integral

Liquid Piston Prover Uncertainty Analysis Spreadsheet

March 25, 2014
Author(s)
John D. Wright, Aaron N. Johnson, Jodie G. Pope
This publication is a spreadsheet that calculates the mass and volume flow uncertainty for a piston prover liquid flow standard based on user inputs of component uncertainties. The calculations use the basis equation and uncertainty analysis presented in

Liquid Flow Meter Calibrations with the 0.1 L/s and 2.5 L/s Piston Provers

January 15, 2014
Author(s)
Jodie G. Pope, John D. Wright, Aaron N. Johnson, Christopher J. Crowley
This document provides a description of the 2.5 L/s and 0.1 L/s liquid flow calibration standards operated by the National Institute of Standards and Technology (NIST) Fluid Metrology Group to provide flow meter calibrations for customers. The 0.1 L/s and

Greenhouse Gas Emissions and Dispersion #2. Comparison of FDS Predictions with Gas Velocity Measurements in the Exhaust Duct of a Stationary Source

April 25, 2013
Author(s)
Kuldeep R. Prasad, Kevin Li, Elizabeth F. Moore, Rodney A. Bryant, Aaron N. Johnson, James R. Whetstone
The burning of fossil fuels remains a major source of greenhouse gases responsible for global warming and climate change. In order to reduce greenhouse gas emissions, it is imperative to develop a capability to accurately measure these emissions from point