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Search Publications by: Andrew D. Koffman (Fed)

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Displaying 26 - 50 of 66

Evaluation of a Capacitance Scaling System

December 1, 2007
Author(s)
Svetlana Avramov-Zamurovic, Andrew D. Koffman, Bryan C. Waltrip, Yicheng Wang
A capacitance scaling system from 10 nF to 100 mF [1], [2] has been implemented at the National Institute of Standards and Technology (NIST). Standard four-terminal-pair (4TP) capacitors are characterized using a capacitance scaling calibration procedure

Dissipation Factors of Fused-Silica Capacitors in the Audio Frequency Range

April 1, 2007
Author(s)
Yicheng Wang, Andrew D. Koffman, Gerald FitzPatrick
We describe dissipation factor measurements of 10 pF fused-silica capacitance standards from 50 Hz to 20 kHz, using a toroidal cross capacitor and a 10 pF nitrogen-filled capacitor as the references. The relative combined standard uncertainties are 0.56x10

Improved 1 kHz Capacitance Calibration Uncertainty

May 30, 2002
Author(s)
Anne-Marie Jeffery, Andrew D. Koffman
Uncertainties for 1 kHz capacitance calibrations have been decreased at the National Institute of Standards and Technology (NIST). The improvements are based on frequency-dependence characterization from 1592 Hz to 1 kHz. The relevant measurements and the

A Capacitance Measurement System Using an Inductive Voltage Divider (IVD) Bridge

July 1, 2001
Author(s)
Bryan C. Waltrip, Andrew D. Koffman, S. Avramov
A new system to characterize the magnitude and phase characteristics of 1 pF to 1 uF capacitance standards over the 50 Hz to 100 kHz frequency range is described. The system has been developed to provide measurement support for LCR meters and general

High-Dimensional Empirical Linear Prediction (HELP) Toolbox, version 2.2

February 28, 2001
Author(s)
Andrew D. Koffman, T. M. Souders, Gerard N. Stenbakken, Hans Engler
The High-Dimensional Empirical Linear Prediction (HELP) Toolbox is an optimization tool designed specifically to meet the requirements of test and measurement engineers. For many electronic devices and instruments, it is not physically or economically

Low-Frequency Impedance Calibrations at NIST

July 1, 2000
Author(s)
Andrew D. Koffman, Yui-May Chang
This paper presents an overview of the low-frequency impedance measurement services offered through the Impedance Calibration Laboratory (ICL) at the National Institute of Standards and Technology (NIST). Emphasis will be given to recent improvements as

The Sensitivity of a Method to Predict a Capacitor's Frequency Characteristic

April 1, 2000
Author(s)
S. Avramov, Andrew D. Koffman, Nile M. Oldham, Bryan C. Waltrip
A joint effort between the U.S. Naval Academy and the National Institute of Standard and Technology (NIST) resulted in the development of a method to characterize the capacitance and dissipation factor of a set of commercial standard four terminal-pair

Software to Optimize the Testing of Mixed-Signal Devices

June 1, 1999
Author(s)
Gerard N. Stenbakken, Andrew D. Koffman, T. M. Souders
New software is now available to help test and measurement engineers optimize the testing of complex electronic devices. Examples of products that are benefiting from this software range from A/D and D/A converters to multi-range precision instruments. The

High-Dimensional Empirical Linear Prediction (HELP) Toolbox User's Guide, Version 2.2

May 1, 1999
Author(s)
Andrew D. Koffman, T. M. Souders, Gerard N. Stenbakken, Hans Engler
This user's guide will assist software users in the understanding of the theory and procedures underlying the High-dimensional Empirical Linear Prediction (HELP) Toolbox, developed for use with the MATLAB(r) mathematical software environment. The HELP