U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications

NIST Authors in Bold

Displaying 49876 - 49900 of 74106

Evaluation of Guarded High-Resistance Hamon Transfer Standards

April 1, 1999
Author(s)
Dean G. Jarrett
An improved design for a guarded transfer standard in the resistance range 1 M ω to 100 G ω is described. Existing transfer standards and their limitations are reviewed along with a description of guard circuit theory. Measurements made to evaluate the

Extension of Voltage Range for Power and Energy Calibrations

April 1, 1999
Author(s)
O. Petersons, Thomas L. Nelson, Nile M. Oldham, Gerald FitzPatrick
A special purpose ac voltage divider system with ratios of 600, 480, 360, 277, and 240 V to 120 V has been developed to extend the range of primary electric power calibrations from 120-600 V at 50 and 60 Hz. The developmental goal has been to realize ac

Fabrication of High-Value Standard Resistors

April 1, 1999
Author(s)
Ronald F. Dziuba, Dean G. Jarrett, L. L. Scott, Andrew J. Secula
The National Institute of Standards and Technology (NIST) has fabricated stable, transportable 10 MΩ} and 1 GΩ} standard resistors for use in an international comparison of high resistances. This fabrication process is being applied to the construction of

Forward

April 1, 1999
Author(s)
Norman B. Belecki
The National Institute of Standards and Technology (NIST) hosted the 1998 Conference on Precision Electromagnetic Measurements (CPEM'98) in the Washington Renaissance Hotel, Washington, DC, the week of July 6-10, 1998. In it, 506 metrologists, physicists

Frequency Comparison of 127 I 2 -Stabilized Nd: YAG Laser

April 1, 1999
Author(s)
F L. Hong, K Ishikawa, J Yoda, J Ye, L -. Ma, John L. Hall
A first international comparison of I 2-stabilized Nd: YAG lasers has been made between the National Research Laboratory of Metrology (NRLM), Tsukuba, Japan, the Joint Institute for Laboratory Astrophysics JILA (formerly the Joint Institute for Laboratory

Generation of Different UHMWPE Particle Shape by Wear Through Surface Texturing

April 1, 1999
Author(s)
H. W. Fang, M C. Shen, U Cho, John A. Tesk, A Christou, Stephen M. Hsu
Ultra-high molecular weight polyethylene (UHMWPE) wear particles in replaced joints have been linked to biochemical reactions that eventually lead to loosening of prosthesis. Several studies have shown that UHMWPE produces a wide range of particle sizes

Guest Editorial

April 1, 1999
Author(s)
Barry A. Bell
The National Institute of Standards and Technology hosted the 1998 Conference on Precision Electromagnetic Measurements (CPEM >98) in the Washington Renaissance hotel during the Week of July 6-10, 1998. The Technical Program included 344 papers given in 32

IEEE Trans on Instrumentation - Forward

April 1, 1999
Author(s)
Norman B. Belecki
The National Institute of Standards and Technology hosted the 1998 Conference on Precision Electromagnetic Measurements (CPEM'98) in Washington, D.C. during the week of July 6-10, 1998. Attendance included 506 metrologists, physicists, and engineers from

Imaging of Acoustic Surface Wave Slowness

April 1, 1999
Author(s)
D Xiang, Nelson N. Hsu, Gerald V. Blessing
An experimental method has been devised for imaging the acoustic surface wave slowness (inverse of the phase velocity) in anisotropic solids. This technique utilizes a specially designed broadband, line-focus transducer to sense the leaky surface waves as

Improving Kinematic Touch Trigger Probe Performance

April 1, 1999
Author(s)
Steven D. Phillips, William T. Estler
Kinematic touch trigger probes are widely used on CMMs. This article gives CMM users advice on how to minimize the systematic errors associated with this class of probes.

Instrumental Aspects of X-Ray Microbeams in the Range Above 1 keV

April 1, 1999
Author(s)
P Dhez, P Chevallier, Thomas B. Lucatorto, Charles Tarrio
X rays were discovered by Roentgen in 1895, just over 100 years ago. Early investigations by Roentgen himself indicated that prisms, lenses, and mirrors were seemingly ineffective for deflecting and focusing x rays. However, the magical ability to look

Internet Commerce for Manufacturing Product Data

April 1, 1999
Author(s)
Curtis H. Parks
Printed circuit assemblies (PCA) typically are designed on computer aided design (CAD) systems, checked, then released for manufacture. The released design description typically consists of a top assembly drawing and a series of data files which are used

Modeling of Bare and Aspirated Thermocouples in Compartment Fires

April 1, 1999
Author(s)
L G. Blevins, William M. Pitts
As part of an effort to characterize the uncertainties associated with temperature measurements in fire environments, models of bare bead single-shielded aspirated, and double-shielded aspirated thermocouples were developed and used to study the effects of
Displaying 49876 - 49900 of 74106