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Search Publications by: Bala Muralikrishnan (Fed)

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Displaying 101 - 125 of 170

A Proposed Interim Check for Field Testing a Laser Trackers 3-D Length Measurement Capability Using a Calibrated Scale Bar as a Reference Artifact

October 1, 2014
Author(s)
Vincent D. Lee, Christopher J. Blackburn, Balasubramanian Muralikrishnan, Daniel S. Sawyer, Mark Meuret, Aaron Hudlemeyer
This paper describes a proposed interim check for field testing a laser tracker’s 3-D length measurement capability using a calibrated scale bar as a reference artifact. The tests described here are constructed to be sensitive to uncompensated errors in

EVALUATION OF A LASER SCANNER FOR LARGE VOLUME COORDINATE METROLOGY - A COMPARISON OF RESULTS BEFORE AND AFTER FACTORY CALIBRATION

October 1, 2014
Author(s)
Massimiliano Ferrucci, Bala Muralikrishnan, Daniel S. Sawyer, Steven D. Phillips, Peter Petrov, Yuri Yakovlev, Andrey Astrelin, Spike Milligan, John Palmateer
Large volume laser scanners are increasingly being used for a variety of dimensional metrology applications. Methods to evaluate the performance of these scanners are still under development and there are currently no documentary standards available. This

Ranging Performance Evaluation of a Laser Scanner

October 20, 2013
Author(s)
Massimiliano M. Ferrucci, Balasubramanian Muralikrishnan, Christopher J. Blackburn, Daniel S. Sawyer, Steven D. Phillips, Vincent D. Lee, Peter Petrov, Yuri Yakovlev, Andrey Astrelin, Spike Milligan, John Palmateer
Large volume laser scanners are used for a variety of purposes, including dimensional metrology of large artifacts, digitization and reverse engineering, as well as historical preservation and archiving. In evaluating the performance of laser scanners, we

VOLUMETRIC PERFORMANCE EVALUATION OF A LASER SCANNER

October 20, 2013
Author(s)
Balasubramanian Muralikrishnan, Massimiliano M. Ferrucci, Daniel S. Sawyer, Grant Gerner, Vincent D. Lee, Christopher J. Blackburn, Steven D. Phillips, Peter Petrov, Yuri Yakovlev, Andrey Astrelin, Spike Milligan, John Palmateer
There are several sources of error in a laser scanner measurement. The optical and material properties of the target, the shape, form, surface texture, color, reflectivity, and orientation of the target in space, environmental effects, etc., all contribute

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

The Effect of Tip Size in Calibration of Surface Roughness Specimens with Rectangular Profiles

September 2, 2013
Author(s)
Jun-Feng Song, Thomas B. Renegar, Johannes A. Soons, Balasubramanian Muralikrishnan, John S. Villarrubia, Xiaoyu A. Zheng, Theodore V. Vorburger
For the calibration of rectangular and trapezoidal profile roughness specimens, stylus tip will increase profile peak width and decrease valley width, which may cause the Ra changes (either increase or decrease, depends on the profile shape). Sometimes the

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

Assessing Ranging Errors as a Function of Azimuth in Laser Trackers and Tracers

April 18, 2013
Author(s)
Balasubramanian Muralikrishnan, Vincent D. Lee, Christopher J. Blackburn, Daniel S. Sawyer, Steven D. Phillips, Wei Ren, Ben Hughes
Tilt and radial error motion of a laser tracker head as it spins about the two axes results in small but measurable ranging and angle errors. The laser tracer, on the other hand, measures range with respect to the center of a high quality stationary sphere

A Model for Geometry-Dependent Errors in Length Artifacts

September 27, 2012
Author(s)
Daniel S. Sawyer, Brian Parry, Christopher J. Blackburn, Balasubramanian Muralikrishnan, Steven D. Phillips
We present a detailed model of dimensional changes in long length artifacts, such as step gauges and ball bars, due to bending under gravity. The comprehensive model is based on evaluation of the gauge points relative to the neutral bending surface. It

Stylus Tip-Size Effect on the Calibration of Periodic Roughness Specimens with Rectangular Profiles

March 21, 2012
Author(s)
Thomas B. Renegar, Johannes A. Soons, Balasubramanian Muralikrishnan, John S. Villarrubia, Xiaoyu A. Zheng, Theodore V. Vorburger, Jun-Feng Song
Stylus instruments are widely used for surface characterization. It is well known that the size and shape of the stylus tip affects the measured surface geometry and parameters. In most cases, increasing the tip size decreases the measured Ra value because

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