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NIST Authors in Bold

Displaying 2026 - 2050 of 2177

Statistical Models for Estimating the Measurement of Pitch in Metrology Instruments

January 1, 1996
Author(s)
Nien F. Zhang, Michael T. Postek, Robert D. Larrabee
The measurement of pitch in metrology instruments is through to be a benign self-compensating function. In the course of issuing the new scanning electron microscope standard SRM 2090, a new algorithm for the measurement of pitch was developed. This is

Strut Structure and Rigid Joint Therefor

January 1, 1996
Author(s)
James E. Potzick
A highly rigid structure is provided using six struts connected at three upper and three lower nodes to upper and lower support structures. The joint assemblies are formed by half- spherical balls attached to the ends of each of the struts, and retained

Stylus Flight in Surface Profiling

January 1, 1996
Author(s)
Jun-Feng Song, Theodore V. Vorburger
In this paper, theoretical and experimental work on stylus flight is described. Experiments on the surfaces of different roughness specimens with sinusoidal, rectangular, triangular and random waveforms support the theoretical model, which predicts stylus

Uncertainty Procedure for NIST Surface Finish and Microform Calibration

January 1, 1996
Author(s)
Jun-Feng Song, Theodore V. Vorburger
An uncertainty procedure is used for reporting the NIST surface finish and microform calibration uncertainties. The combined standard uncertainty is a combination of the uncertainty from the geometric non-uniformity of the measured surface, and the

Using a Potentiostat to Model In-Process Electromechanical Dressing

January 1, 1996
Author(s)
Robert S. Polvani, A Fraker, Christopher J. Evans
In-process electrochemical dressing insures true, sharp, stable wheels for efficient ceramic grinding. To better implement electrochemical dressing, we couple laboratory studies based on a potentiostat with shop floor grinding runs. To do this, a calomel

Wavelength-Shift Interferometry: Using a Dither to Improve Accuracy

January 1, 1996
Author(s)
Jack A. Stone Jr., Alois Stejskal, Lowell P. Howard
A dither in path length can dramatically improve the accuracy of wavelength-shift methods used for absolute distance interferometry. Here we report how a dither improves the accuracy of absolute distance measurement by two orders of magnitude, reducing

The ADACS Implementation of the UTAP Architecture

December 1, 1995
Author(s)
Robert Russell, John L. Michaloski, Keith A. Stouffer
The Advanced Deburring and Chamfer System is robotic workcell designed to put precision chamfers on parts made with hard metals. The project was funded by the United States Navy so that the technology developed could be applied to their air defense systems

Visualization of Surface Figure Using Zernike Polynomials

December 1, 1995
Author(s)
Christopher J. Evans, R E. Parks, P Sullivan, John S. Taylor
Commercial software in modern interferometers used in optical testing frequently fit the wave-front or surface-figure error to Zernike polynomials; typically 37 coefficients are provided. We provide visual representations of these data in a form that may

Stylus Technique for Direct Verification of Rockwell Diamond Indenters

November 23, 1995
Author(s)
Jun-Feng Song, F Rudder, Theodore V. Vorburger, J Smith
Based on a stylus technique, a microform calibration system was developed at NIST for the direct verification of Rockwell diamond indenters. The least-squares radius and profile deviations, cone angle and cone flank straightness, and the holder axis

Blind Estimation of Tip Geometry from Noisy Images

November 2, 1995
Author(s)
John S. Villarrubia
Broadening of image features due to non-vanishing tip size is a well-known imaging artifact in scanned probe microscopy (SPM) topographs. This need not be a serious limitation for some types of metrology (e.g. pitch or height), but it is significant for

Measurement of the self-broadening rate coefficients of the cesium resonance lines

November 1, 1995
Author(s)
Zeina J. Kubarych, J Huennekens, R K. Namiotka, J Sagle
The self-broadening rate coefficients of the cesium D1 [62S1/2 - 62P1/2] and D2 [62S1/2 - 62P3/2] resonance lines are determined from the 62P1/2 --> 62D3/2, 62D3/2---> 72D3/2 and 62P3/2 --> 72D5/2 transition lineshapes, which are mapped out using single

Test of a Slow Off-Axis Parabola at it

November 1, 1995
Author(s)
R E. Parks, Christopher J. Evans, Lianzhen Shao
We describe the interferometric testing of a slow (f/16 at the center of curvature) off-axis parabola, intended for use in an x-ray spectrometer, that uses a spherical wave front matched to the mean radius of the asphere. We find the figure error in the

1/N Feynman Machines as a Path to Ultraminiaturization

September 1, 1995
Author(s)
E C. Teague
The possibility of implementing Feynman''s proposal for achieving ultraminiaturization by an iterative process of three-dimensional machines making ever-smaller three-dimensional machines is considered in the nature of a thought experiment. A large array

Microform Calibration Uncertainties of Rockwell Diamond Indenters

September 1, 1995
Author(s)
Jun-Feng Song, F Rudder, Theodore V. Vorburger, J Smith
National and international comparisons in Rockwell hardness tests show significant differences. Uncertainties in the geometry of the Rockwell diamond indenters are largely responsible for these differences. By using a stylus instrument, with a series of

Rapidly Renewable Polishing Lap

September 1, 1995
Author(s)
Christopher J. Evans, R E. Parks
Textured laps can be created by slumping uniform thin films of appropriate materials over textured substrates that have been generated to the required figure. The film can easily be replaced and the lap shape is invariant since the lap substrate never

Frequency Stabilization of a Green He-Ne Laser

August 20, 1995
Author(s)
Jack A. Stone Jr., Alois Stejskal
A new process for stabilizing the frequency of commercially available 543 nm He-Ne lasers is described. The stabilization method is based on anomalous dispersion of the gain medium. A total of four green lasers have been stabilized - two at the National
Displaying 2026 - 2050 of 2177
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