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Search Publications by: Theodore D. Doiron (Assoc)

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Displaying 1 - 25 of 37

Sphere Diameter Interferometry with Nanometer Uncertainty

February 20, 2020
Author(s)
Eric S. Stanfield, John R. Stoup, Michael P. Braine, Theodore D. Doiron
In this paper we present both the design details and uncertainty budget for a National Institute of Standards and Technology (NIST)-developed high-accuracy Fizeau-type interferometer specifically adapted to measurement sphere diameter. To do this, we

Dimensional Measurement Uncertainty from Data. Part 2: Uncertainty R&R

July 1, 2016
Author(s)
Theodore D. Doiron
While check standards will eventually give the most accurate uncertainty for a calibration procedure, the time and expense can be discouraging. Another common method, standard Gage Repeatability and Reproducibility study does not produce anything like the

Dimensional Review of Scales for Forensic Photography

November 25, 2015
Author(s)
Massimiliano Ferrucci, Theodore D. Doiron, Robert M. Thompson, John Jones, Adam J. Freeman, Janice A. Neiman
Scales for forensic photography provide a geometrical reference in the photographic documentation of a crime scene. A common scale used by investigators is a plastic, L-shaped ruler that allows for a dimensional reference in the photographic documentation

Using Check Standard Data to Simplify Uncertainty Estimates

July 1, 2015
Author(s)
Theodore D. Doiron
Uncertainty has proven difficult to implement in calibrations labs. The subject has mathematics and statistics that are part of normal scientific research but are seldom found among working metrologists in small calibration labs. There is, however, a

Two Applications of Small Feature Dimensional Measurements on a CMM with a Fiber Probe

September 4, 2013
Author(s)
Eric S. Stanfield, Bala Muralikrishnan, Theodore D. Doiron, Xiaoyu Alan Zheng, Shahram Orandi, david Duquette
We describe two interesting applications of dimensional measurements performed using a contact fiber probe on a commercial Coordinate Measuring Machine (CMM). Both examples involve artifacts that serve as material standards and contain features in the 100

Applications of Profile Filtering in the Dimensional Metrology of Fuel Cell Plates

May 14, 2013
Author(s)
Balasubramanian Muralikrishnan, Wei Ren, Eric S. Stanfield, Dennis S. Everett, Xiaoyu A. Zheng, Theodore D. Doiron
We describe the application of several surface profile filters as an enabling tool in the dimensional measurements of an engineering artifact, namely, a fuel cell plate. We recently reported work on the development of a non-contact system for dimensional

High Accuracy Measurements Using a Scanning System with a Single Point Triangulation Sensor

May 13, 2013
Author(s)
Theodore D. Doiron, Wei Ren, Eric S. Stanfield, Balasubramanian Muralikrishnan, Christopher J. Blackburn
The capabilities of non-contact laser spot triangulation sensors for high accuracy measurements have slowly increased over the past decade, and now have usable resolution below 0.1 µm. The Dimensional Metrology Group has developed a simple scanning system

Performance Evaluation Experiments on a Laser Spot Triangulation Probe

November 25, 2011
Author(s)
Balasubramanian Muralikrishnan, Wei Ren, Dennis S. Everett, Eric S. Stanfield, Theodore D. Doiron
Laser triangulation probes are increasingly used for dimensional measurements in a variety of applications. At the National Institute of Standards and Technology, we have recently explored the use of laser spot triangulation probes to determine dimensional

NON-CONTACT DIMENSIONAL MEASUREMENTS OF BIPOLAR FUEL CELL PLATES

November 15, 2011
Author(s)
Balasubramanian Muralikrishnan, Wei Ren, Dennis S. Everett, Eric S. Stanfield, Theodore D. Doiron
Non-contact dimensional measurement of fuel cell plates is critical to the eventual rapid manufacture by supporting in-process measurement and control. This need has been identified by the Department of Energy’s Hydrogen Program, and by numerous

Dimensional Metrology of Bipolar Fuel Cell Plates Using Laser Spot Triangulation Probes

March 22, 2011
Author(s)
Balasubramanian Muralikrishnan, Wei Ren, Dennis S. Everett, Eric S. Stanfield, Theodore D. Doiron
As in any engineering component, manufacturing a bipolar fuel cell plate for a polymer electrolyte membrane (PEM) hydrogen fuel cell power stack to within its stated design tolerances is critical in achieving the intended function. In a bipolar fuel cell

Gauge Blocks - A Zombie Technology

May 1, 2008
Author(s)
Theodore D. Doiron
Gauge blocks have been the primary method for disseminating length traceability for over 100 years. Their longevity was based on two things: it was relatively inexpensive to deliver very high accuracy to users, and the technical limitation that the range

Early Results From the NIST M48 CMM in the New AML Facility

March 3, 2006
Author(s)
John R. Stoup, Bryon S. Faust, Theodore D. Doiron
The Advanced Measurement Laboratory at NIST in Gaithersburg has already provided real, measurable improvement in some dimensional metrology measurement processes at NIST, most notably in the performance of the NIST Moore M48 coordinate measuring machine1

New Capabilities At NIST In Dimensional Metrology

January 1, 2005
Author(s)
Theodore D. Doiron, Eric S. Stanfield, Bryon S. Faust, John R. Stoup, Mary Abbott
A number of new or revised services in dimensional metrology are presented. Included are: a lower cost, high accuracy calibration for sphere diameter; reduced uncertainty in roundness calibration; a new instrument for measurement of the thermal expansion

Deformation of Gauge Blocks

January 1, 2002
Author(s)
Theodore D. Doiron, Eric S. Stanfield, Dennis S. Everett
When a force is exerted on any material, the material deforms. Most of the time the effect is small and is neglected. In the measurement of gauge blocks, where the uncertainty goal is stated in nanometers, the deformation is a very large effect, and can be

Video-Based Metrology

January 1, 2002
Author(s)
Theodore D. Doiron, Marilyn N. Abrams, Tsai Hong Hong, Michael O. Shneier
With the rapid growth of video-based measurement and inspection systems, we would like to determine the extent to which industry needs calibration artifacts and standardized methods for video metrology. We hope to open a dialog among users for discussing

Video-Based Metrology

January 1, 2002
Author(s)
Theodore D. Doiron, John R. Stoup, Marilyn N. Abrams, Tsai Hong Hong
Video cameras are increasingly used to make dimensional measurements. Many of these systems use interpolation of the pixel data, with some systems claiming to find edges with precision of l/100 of a pixel. We have studied the response of single pixels of a

Accuracy and Versatility of the NIST M48 Coordinate Measuring Machine

October 1, 2001
Author(s)
John R. Stoup, Theodore D. Doiron
The NIST Is continuing to develop the ability to perform accurate, traceable measurements on a wide range of artifacts using a very precise, error-mapped coordinate measuring machine (CMM). The NIST M48 CMM has promised accuracy and versatility for many

A Careful Consideration of the Calibration Concept

March 1, 2001
Author(s)
Steven D. Phillips, William T. Estler, Theodore D. Doiron, K Eberhardt, M Levenson
This paper is a detailed discussion of the technical aspects of the calibration process with emphasis on the definition of the measurand, the conditions under which the calibration results are valid, and the subsequent use of the calibration results in

A Careful Consideration of the Calibration Concept

January 1, 2001
Author(s)
Steven D. Phillips, William T. Estler, Theodore D. Doiron, K Eberhardt, M. Levenson
This paper is a detailed discussion of the technical aspects of the calibration process with emphasis on the definition of the measurand, the conditions under which the calibration results are valid, and the subsequent use of the calibration results in

Video Based Metrologly

December 1, 2000
Author(s)
Theodore D. Doiron, Tsai H. Hong, John R. Stoup, Marilyn N. Abrams
Video cameras are increasingly used to make dimensional measurements. Many of these systems use interpolation of the pixel data, with some systems claiming to find edges with precision of 1/100 of a pixel. We have studied the response of single pixels of a