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Metrology

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Displaying 1301 - 1325 of 2730

Flat frequency response in the electronic measurement of the Boltzmann constant

July 1, 2012
Author(s)
Jifeng Qu, Samuel Benz, Yang Fu, Jianqiang Zhang, Horst Rogalla, Alessio Pollarolo
A new quantum voltage calibrated Johnson noise thermometer (JNT) was developed at NIM to demonstrate the electrical approach that determines the Boltzmann constant k by comparing electrical and thermal noise power. A measurement with integration period of

Method for Ensuring Accurate AC Waveforms with Programmable Josephson Voltage Standards

July 1, 2012
Author(s)
Charles J. Burroughs, Alain Rufenacht, Samuel P. Benz, Paul D. Dresselhaus
The amplitudes of stepwise-approximated sine waves produced by programmable Josephson voltage standards (PJVSs) are not intrinsically accurate because the transitions between the quantized voltages depend on numerous conditions. We have developed a method

Standardizing Rectangular Metallic Waveguides for Terahertz Applications

July 1, 2012
Author(s)
Ronald A. Ginley, N M. Ridler
This paper describes an on-going activity to develop an international document standard for defining rectangular metallic waveguides for use in the submillimeter-wave/terahertz frequency range. The IEEE's Microwave Theory & Techniques Society (MTT-S) is

Testing Phasor Measurement Units using the IEEE 1588 Precision Time Protocol

July 1, 2012
Author(s)
Julien M. Amelot, Gerard N. Stenbakken
As the electric power grid is changing to a smarter more dynamically controlled system, there is increasing need for measurements that show the global status of the system for wide-area monitoring and control. These measurements require time

Next Generation Packaging, Kitting, and Palletizing: Can one robot do it all?

June 28, 2012
Author(s)
Rajmohan (. Madhavan, Stephen B. Balakirsky, Craig I. Schlenoff
A seminar titled "Next Generation Packaging, Kitting, and Palletizing: Can one robot do it all?" was held on February 9th 2012 at the Material Handling Industry of America (MHIA) MODEX show in Atlanta, GA. The seminar primarily focused on whether systems

Safe Control of Manufacturing Vehicles Research Towards Standard Test Methods

June 28, 2012
Author(s)
Roger V. Bostelman, William P. Shackleford, Geraldine S. Cheok, Kamel S. Saidi
The National Institute of Standards and Technology's Intelligent Systems Division has been researching several areas leading to safe control of manufacturing vehicles to improve AGV safety standards. The research areas include: - Automated guided vehicle

Compressed-liquid densities of two highly polar + non-polar binary systems

June 24, 2012
Author(s)
Stephanie L. Outcalt, Arno R. Laesecke
The binary systems ethanol + 2,2,4-trimethylpentane and 2-butanol + 2,2,4-trimethylpentane were studied as models for blends of gasoline with biofuels. Their densities were measured with a vibrating-tube densimeter at compressed-liquid states of three

TESTING LONG-WAVELENGTH ACOUSTIC FLOWMETER CONCEPTS FOR FLUE GAS FLOWS

June 22, 2012
Author(s)
Lee J. Gorny, Keith A. Gillis, Michael R. Moldover
As a part of NIST’s program to standardize measurements of greenhouse gas emissions, we are developing a long-wavelength acoustic flowmeter (LWAF) for accurate, economical measurements of exhaust flows from coal-burning power plants. Measurements of the

Airspeed Calibration Services: Laser Doppler Anemometer Calibration and Its Uncertainty

June 20, 2012
Author(s)
Iosif I. Shinder, Michael R. Moldover, J. M. Hall, Mike Duncan, Joe Keck
The National Institute of Standards and Technology (NIST) and the Oak Ridge National Laboratory (ORNL) are improving their airspeed calibration services. Both laboratories use spinning disks to generate linear velocities that are traceable to NIST’s length

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

USARSim/ROS: A Combined Framework for Robotic Control and Simulation

June 20, 2012
Author(s)
Stephen B. Balakirsky, Zeid Kootbally
The Robot Operating System (ROS) has been steadily gaining popularity among robotics researchers as an open source framework for robot control. The Unified System for Automation and Robot Simulation (USARSim) has been used for many years by robotics

A New Convexity Measurement for 3D Meshes

June 16, 2012
Author(s)
Afzal A. Godil, Zhouhui Lian
This paper presents a novel convexity measurement for 3D meshes. The new convexity measure is calculated by minimizing the ratio of the summed area of valid regions in a mesh’s six views, which are projected on faces of the bounding box whose edges are

Technology Readiness Levels for Randomized Bin Picking

June 13, 2012
Author(s)
Jeremy A. Marvel, Roger D. Eastman, Geraldine S. Cheok, Kamel S. Saidi, Tsai Hong Hong, Elena R. Messina
A proposal for the utilization of Technology Readiness Levels to the application of unstructured bin picking is discussed. A special session was held during the 2012 Performance Metrics for Intelligent Systems workshop to discuss the challenges and

High Confidence Level Calibration for AFM Based Fracture Testing of Nanobeams

June 11, 2012
Author(s)
Scott Grutzik, Richard S. Gates, Yvonne B. Gerbig, Robert F. Cook, Melissa Hines, Alan Zehnder
When designing micro- or nanoelectromechanical systems, (MEMS and NEMS), it is important to consider whether structural elements will withstand loads experienced during operation. Fracture behavior at length scales present in MEMS and NEMS is much di erent

Tensile behavior of single PPTA fibers measured by the Kolsky bar using the direct fiber clamping method

June 11, 2012
Author(s)
Jae Hyun Kim, Nathanael A. Heckert, Stefan D. Leigh, Haruki Kobayashi, Walter G. McDonough, Richard L. Rhorer, Kirk D. Rice, Gale A. Holmes
The Kolsky bar test has been widely used in measuring material behavior under high strain rate conditions. In particular, this methodology has been used to characterize the high strain rate behavior of polymer and polymer composites during ballistic impact

Assessing the Effect of Inconsistent Assessors on Summarization Evaluation

June 8, 2012
Author(s)
Karolina K. Owczarzak, Peter Rankel, Hoa T. Dang, John M. Conroy
We investigate the consistency of human assessors involved in summarization evaluation to understand its effect on system ranking and automatic evaluation techniques. Using Text Analysis Conference data, we measure annotator consistency based on human

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
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