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Author: theodore doiron
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21. Probing of Two-Dimensional Grid Patterns by Means of Camera Based Image Processing
Martin Schroeck, Theodore D Doiron
Camera based probes and machine vision have found increased use in coordinate measuring machines over the past years and the calibration of artifacts for these probes has become an important task for NIST. Until recently these artifacts have been ca ...
22. Effects of Defocus and Algorithm on Optical Step Height Calibration
Theodore D Doiron, Theodore Vincent Vorburger, P Sullivan
Defocus effects on step height measurements by interferometric microscopy are estimated using different algorithms to calculate the step height. The interferometric microscope is a Mirau-type with a 20x objective and a numerical aperture (NA) of 0.4. ...
23. Two-Dimensional Calibration Artifact and Measurement Methodology
Richard M Silver, Theodore D Doiron, William B. Penzes, S Fox, Edward A Kornegay, S Rathjen, M Takac, D Owen
In this paper, we describe our design and the manufacturing of a two-dimensional grid artifact of chrome on quartz on a 6 inch by 6 inch by .250 glass blank. The design has been agreed upon by a number of SEMI participants working on a two-dimensiona ...
24. Case Against Optical Gauge Block Metrology
Theodore D Doiron, Dennis S Everett, Bryon S. Faust, Eric S Stanfield, John Richard Stoup
The current definition of length of a gage block is a very clever attempt to evade the systematic errors associated with the wringing layer thickness and optical phase corrections. In practice, there are very large systematic operator and surface eff ...
25. Minimizing Errors in Phase Change Correction Measurements for Gage Blocks Using a Spherical Contact Techniques
John Richard Stoup, Bryon S. Faust, Theodore D Doiron
One of the most elusive measurement elements in gage block interferometry is the correction for the phase change on reflection. Techniques used to quantify this correction have improved over the years, but the measurement uncertainty has remained rel ...
26. Uncertainty and Dimensional Calibrations
Theodore D Doiron, John Richard Stoup
The calculation of uncertainty for a measurement is an effort to set reasonable bounds for the measurement result according to standardized rules. Since every measurement produces only an estimate of the answer, the primary requisite of an uncertaint ...
27. Glass and Dimensional Metrology
Theodore D Doiron
Ordinary glass, even good optical quality glass, will shrink up to 20 micrometers/meter over the first few years after its manufacture. Gages made of glass are therefore not suitable as high accuracy artifacts unless they are calibrated often. Better ...
28. The Gage Block Handbook
Monograph (NIST MN)
Theodore D Doiron, John S Beers
Gage blocks are the primary method used by industry to standardize the measurement of dimension. This work discusses every aspect of gage block calibration, including definitions, characteristics of gage blocks, calibration by interferometry and mech ...
29. A High Accuracy Micrometer for Diameter Measurements of Cylindrical Standards
John Richard Stoup, Theodore D Doiron
NIST has developed a new instrument to measure cylindrical standards including thread wires and plain plug gages. The instrument uses a laser interferometer system which is coupled with an air bearing linear motion slide and precise contact geometry ...