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Search Publications by: John D. Wright (Assoc)

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Displaying 51 - 75 of 134

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

Performance of Coriolis Meters in Transient Gas Flows

March 17, 2014
Author(s)
Jodie G. Pope, John D. Wright
NIST evaluated the instantaneous and totalized flow measured by two commercial coriolis meters under transient flow, pressure, and temperature conditions using a Transient Flow Facility (TFF) developed for this purpose. During a simulated cascade fill of a

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

Improved Nozzle Manifold for Gas Flow Calibrations

June 20, 2012
Author(s)
Aaron N. Johnson, Chunhui Li, John D. Wright, Gina M. Kline, Christopher J. Crowley
We developed a new nozzle manifold that reduced the uncertainty of flow calibrations from 0.09 % to as low as 0.074 % for flows of air up to 0.84 kg/s (43 000 L/min at reference conditions of 101.325 kPa and 293.15 K). The nozzle manifold also reduces the

Tests of the Extended Lee Model Using Three Different Turbine Meters

June 20, 2012
Author(s)
Jodie G. Pope, John D. Wright, Sherry D. Sheckels
We report additional tests of our “extended Lee model” for calibrating turbine meters. The model accounts for 1) Reynolds number (Re) dependent drag and lift, 2) bearing static drag and 3) bearing viscous drag. Initially, we tested this model using a dual

Calibration of Laminar Flow Meters for Process Gases

June 1, 2012
Author(s)
John D. Wright, Thiago Cobu, Robert F. Berg, Michael R. Moldover
We calibrated three models of commercially-manufactured, laminar flow meters (LFMs) at four pressures (100 kPa, 200 kPa, 300 kPa, and 400 kPa) with five gases (N2, Ar, He, CO2, and SF6) over a 10:1 flow range using NIST’s primary flow standards as

Extended Lee model for the turbine meter & calibrations with surrogate fluids

May 1, 2012
Author(s)
Jodie G. Pope, John D. Wright, Aaron N. Johnson, Michael R. Moldover
We developed a physical model termed the “extended Lee model” for calibrating turbine meters to account for 1) fluid drag on the rotor, 2) bearing static drag and 3) bearing viscous drag. We tested the extended Lee model using a dual rotor, 2.5 cm diameter

Accurate Measurements of Process Gas Flow with Laminar Flow Meters

October 15, 2010
Author(s)
Thiago Cobu, Robert F. Berg, John D. Wright, Michael R. Moldover
We calibrated three models of commercially-manufactured, laminar flow meters (LFMs) with nitrogen at four pressures (100 kPa, 200 kPa, 300 kPa, and 400 kPa) over a 10:1 flow range using NIST’s primary flow standards and a physical model. Without additional

Properties for Accurate Gas Flow Measurements

October 15, 2010
Author(s)
John D. Wright
Accurate gas properties are needed to take full advantage of the low uncertainties provided by NIST’s Gas Flow Calibration Services. If a flowmeter user and NIST use different values for these properties (molecular mass, compressibility, density, viscosity

NIST Calibration Services for Hydrometers.

April 19, 2010
Author(s)
John D. Wright, Vern E. Bean
The National Institute of Standards and Technology (NIST) provides calibration services for hydrometers used to measure liquid density. Hydrometers with scales for density, specific gravity, proof spirit for alcohol solutions, API degrees for petroleum

Performance of Critical Flow Venturis under Transient Conditions

April 13, 2010
Author(s)
John D. Wright
Critical flow venturis (CFVs) can be used to measure flow under transient pressure and flow conditions with uncertainties of 0.13 % or less (95 % confidence level). Blow-down tests transferred 630 g of nitrogen during a 100 s interval from an unregulated

Gas Flowmeter Calibrations With the 26 m 3 PVTt Standard

November 25, 2009
Author(s)
Aaron N. Johnson, John D. Wright
This document describes NIST s 26 m3 pressure, volume, temperature, and time (PVTt) primary flow standard. This standard is used to calibrate gas flow meters over a range extending from 200 standard L/min to 77,000 standard L/min where the reference