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Search Publications by: Daniel S. Sawyer (Fed)

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Displaying 51 - 71 of 71

A Low Cost Fiducial Reference for Computed Tomography

November 11, 2008
Author(s)
Zachary H. Levine, Steven Grantham, Daniel S. Sawyer, Anthony P. Reeves, David F. Yankelevitz
Rationale and Objectives. To detect the growth in lesions, it is necessary to ensure that the apparent changes in size are above the noise floor of the system. By introducing a fiducial reference, it may be possible to detect smaller changes in lesion size

Calibration of a Computer Assisted Orthopedic Hip Surgery Phantom

November 4, 2008
Author(s)
Daniel S. Sawyer, Nicholas G. Dagalakis, Craig M. Shakarji, Yong Sik Kim
Orthopedic surgeons have identified a need for calibration artifacts (phantoms) to establish the traceability (to the SI unit of length) of measurements performed with Computer Assisted Orthopedic Surgery (CAOS) systems. These phantoms must be lightweight

Performance Evaluation of Laser Trackers

September 15, 2008
Author(s)
Balasubramanian Muralikrishnan, Daniel S. Sawyer, Christopher J. Blackburn, Steven D. Phillips, Bruce R. Borchardt, William T. Estler
The American Society for Mechanical Engineers (ASME) recently released the ASME B89.4.19 Standard [1] on performance evaluation of spherical coordinate instruments such as laser trackers. At the National Institute of Standards and Technology (NIST), we can

Laser Tracker Testing at NIST Using the ASME B89.4.19 Standard

January 1, 2007
Author(s)
Balasubramanian Muralikrishnan, Christopher J. Blackburn, Daniel S. Sawyer, Bruce R. Borchardt, William T. Estler, Steven D. Phillips
While the versatility and economics of laser trackers are quite appealing, the ability to assess their accuracy and to compare various brands has been limited by a lack of a national or international standard that encompasses testing and traceability

Large-Scale Metrology Instrument Performance Evaluations at NIST

January 1, 2006
Author(s)
William T. Estler, Daniel S. Sawyer, Bruce R. Borchardt, Steven D. Phillips
The ASME B89 Committee on Dimensional Metrology has approved a new American National Standard B89.4.19 - Performance Evaluation of Laser Based Spherical Coordinate Measurement Systems. This Standard, to be published in 2006, specifies test methods for

Validation of CMM Task Specific Measurement Uncertainity Software

August 1, 2003
Author(s)
M P. Henke, J M. Baldwin, K Summerhays, B Rasnick, P Murray, Daniel S. Sawyer, Bruce R. Borchardt, Steven D. Phillips, Craig M. Shakarji
Task specific CMM measurement uncertainty statements can be generated using computer (Monte Carlo) simulation. REcently, commercial products using this powerful technique have become available; however they typically involve megabytes of code inaccessible

The Validation of CMM Task Specific Measurement Uncertainty Software

January 1, 2003
Author(s)
Steven D. Phillips, Bruce R. Borchardt, A Abackerli, Craig M. Shakarji, Daniel S. Sawyer, P Murray, B Rasnick, K Summerhays, J M. Baldwin, M P. Henke
Task specific CMM measurement uncertainty statements can be generated using computer (Monte Carlo) simulation. Recently, commercial products using this powerful technique have become available; however they typically involve megabytes of code inaccessible

A Laser Tracker Calibration System

January 1, 2002
Author(s)
Daniel S. Sawyer, Bruce R. Borchardt, Steven D. Phillips, Charles Fronczek, William T. Estler
We describe a laser tracker calibration system developed for frameless coordinate metrology systems. The system employs a laser rail to provide an 'in situ' calibrated length standard that is used to test a tracker in several different configurations. The

A Novel Artifact for Testing Large Coordinate Measuring Machines

January 1, 2001
Author(s)
Steven D. Phillips, Daniel S. Sawyer, Bruce R. Borchardt, D E. Ward, D E. Beutel
We present a high accuracy artifact useful for the evaluation of large CMMs. This artifact can be physically probed by the CMM in contrast to conventional techniques that use purely optical methods such as laser interferometers. The system can be used over

A Novel Artifact for Testing Large Coordinate Measuring Machines

January 1, 2000
Author(s)
Steven D. Phillips, Daniel S. Sawyer, Bruce R. Borchardt, David E. Ward, D E. Beutel
We present a high accuracy artifact useful for the evaluation of large CMMs. This artifact can be physically probed by the CMM in contrast to conventional techniques that use purely optical methods such as laser interferometers. The system can be used over

A Constrained Monte Carlo Simulation Method for the Calculation of CMM Measurement Uncertainty

January 1, 1999
Author(s)
Steven D. Phillips, Bruce R. Borchardt, Daniel S. Sawyer, William T. Estler, K Eberhardt, M Levenson, Marjorie A. McClain, Ted Hopp
We describe a Monte Carlo simulation technique where known information about a metrology system is employed as a constraint to distinguish the errors associated with the instrument under consideration from the set of all possible instrument errors. The

The Calculation of CMM Measurement Uncertainty via The Method of Simulation by Constraints

January 1, 1997
Author(s)
Steven D. Phillips, Bruce R. Borchardt, Daniel S. Sawyer, William T. Estler, David E. Ward, K Eberhardt, M. Levenson, Marjorie A. McClain, B Melvin, Ted Hopp, Y Shen
The calculation of task specific measurement uncertainty when using coordinate measuring machines is an important and challenging task. Current methods to address this issue use simulation techniques (e.g., the virtual CMM) where the propagation of known

NIST SRM 9983 High Rigidity Ball-Bar Stand User Manual

June 1, 1995
Author(s)
Daniel S. Sawyer, Steven D. Phillips, Gregory W. Caskey, Bruce R. Borchardt, David E. Ward, P Snoots
This document is the user manual for the NIST SRM 9983 High Rigidity Ball Bar Stand. The manual contains a list of the components that are included as part of the unit. Complete instructions for setting up and assembling the stand to support a ball bar for

Interim testing artifact (ITA) : a performance evaluation system for coordinate measuring machines (CMMs) : user manual

February 1, 1995
Author(s)
Amy Singer, J Land, Steven D. Phillips, Daniel S. Sawyer, Bruce R. Borchardt, Gregory W. Caskey, D Ward, P Snoots, B Faust
The Interim Testing Artifact (ITA) is designed to quickly test CMMs for performance problems so that they can be repaired before significant numbers of good parts are erroneously rejected (or bad parts accepted) by the CMM. Frequent testing using the ITA

A Users' Guide to NIST SRM 2084: CMM Probe Performance Standards

June 1, 1994
Author(s)
Gregory W. Caskey, Steven D. Phillips, Bruce R. Borchardt, David E. Ward, Daniel S. Sawyer
Standard Reference Materials (SRMs) as defined by the National Institute of Standards and Technology (NIST) are well-characterized materials, produced in quantity and certified for one or more physical or chemical properties. They are used to assure the

A Novel CMM Interim Testing Artifact

January 1, 1994
Author(s)
Steven D. Phillips, Bruce R. Borchardt, Gregory W. Caskey, David E. Ward, Bryon S. Faust, Daniel S. Sawyer
NIST is currently developing equipment and techniques to rapidly access the performance of Coordinate Measuring machines (CMMs). This will allow the frequent testing of CMMs to insure that they measure parts accurately. A novel interim testing artifact