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Search Publications by: Jon R. Pratt (Fed)

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Displaying 76 - 100 of 115

Precision and Accuracy of Thermal Calibration of Atomic Force Microscopy Cantilevers

January 1, 2006
Author(s)
G A. Matei, E J. Thoreson, Jon R. Pratt, David B. Newell, N A. Burnham
To have confidence in force measurements made with atomic force microscopes (AFMs), the spring constant of the AFM cantilevers should be known with good precision and accuracy, topics not yet thoroughly treated in the literature. In this study, we compared

SI Realization of Small Forces Using an Electrostatic Force Balance

January 1, 2006
Author(s)
Jon R. Pratt, John A. Kramar
We describe the realization of micronewton forces in a fashion consistent with the International System of Units (SI) using the National Institute of Standards and Technology (NIST) electrostatic force balance. A comparison between deadweight and

Use of Transfer Artifacts for Small Force Measurement

January 1, 2006
Author(s)
Gordon A. Shaw, Jon R. Pratt, Richard S. Gates, Mark Reitsma
In order for the atomic microscope (AFM) to be used in truly quantatitive studies, a basis within the international system of units (SI) must be established. In order to do this, the microfabricated cantilevers typically used for AFM force measurements

Development of Traceable Small Force Standards

June 1, 2005
Author(s)
Gordon A. Shaw, Jon R. Pratt
Although instrumented indentation and atomic forcve microscope (AFM) are utilized extensively for the measurement of forces in the piconewton to millinewton regime, accurate calibration of these forces remains an obstacle to quantitative research

Traceable Force Metrology for Micronewton Level Calibration

October 1, 2004
Author(s)
Jon R. Pratt, Richard Seugling
The research presented in this abstract concerns the calibration and implementation of a prototype secondary force standard to disseminate the SI (Syst?me International d''unit?s) unit of force ranging from 5.0 mN to 5.0 mN. The elastic-force measuring

Progress Towards SI Traceable Force Metrology for Nanomechanics

January 1, 2004
Author(s)
David B. Newell, Eric P. Whitenton, John A. Kramar, Jon R. Pratt, Douglas T. Smith
This paper is based, in its entirety, on NIST-approved publications: Calibration of Piezoresistive Cantilever Force Sensors Using the NIST Electrostatic Force Balance, The NIST Electrostatic Force Balance Experiment, The NIST Microforce Realization and

Progress Towards Systeme International d'Unites Traceable Force Metrology for Nanomechanics

January 1, 2004
Author(s)
Jon R. Pratt, Douglas T. Smith, David B. Newell, John A. Kramar, Eric P. Whitenton
Recent experiments with the National Institute of Standards and Technology (NIST) Electrostatic Force Balance (EFB) have achieved agreement between an electrostatic force and a gravitational force of 10^(-5) N to within a few hundred pN/¿N. This result

The NIST Microforce Realization and Measurement Project

April 1, 2003
Author(s)
David B. Newell, Edwin R. Williams, John A. Kramar, Jon R. Pratt, Douglas T. Smith
The National Institute of Standards and Technology (NIST) has launched a five-year Micro-force Realization and Measurement project focusing on the development of an instrument and laboratory capable of realizing and measuring the SI unit of force below

Probe-Force Calibration Experiments Using the NIST Electrostatic Force Balance

January 1, 2003
Author(s)
Jon R. Pratt, David B. Newell, John A. Kramar, J Mulholland, Eric P. Whitenton
The sensitivity of a piezoresistive cantilever force sensor has been determined by probing the weighing pan of the NIST prototype electrostatic force balance. In this experiment, micronewton contact forces between a force probe and the balance''s weighing

Compact Force Sensors for Low-Force Mechanical Probe Calibration

September 1, 2002
Author(s)
Jon R. Pratt, Douglas T. Smith, S Woody
The loading mechanisms of instrumented indentation machines are often calibrated using deadweights. In many cases, due to the geometry of the loading frame, the applied deadweight is tensile, while the indentation leads to be measured are compressive. In

Compact Force Sensors for Low-Force Mechanical Probe Calibration

June 1, 2002
Author(s)
Douglas T. Smith, S Woody, Jon R. Pratt
The loading mechanisms of instrumented indentation machines are often calibrated using deadweights. In many cases, due to the geometry of the loading frame, the applied deadweight is tensile, while the indentation leads to be measured are compressive. In

The NIST Microforce Realization and Measurement Project

June 1, 2002
Author(s)
David B. Newell, Jon R. Pratt, John A. Kramar, Douglas T. Smith, Edwin R. Williams
The National Institute of Standards and Technology (NIST) has launched a five-year Microforce Realization and Measurement project focusing on the development of an instrument and laboratory capable of realizing and measuring the SI unit of force below

The NIST Microforce Realization and Measurement Project

June 1, 2002
Author(s)
David B. Newell, Jon R. Pratt, John A. Kramar, Douglas T. Smith, Edwin R. Williams
The National Institute of Standards and Technology (NIST) has launched a five-year Micro-force Realization and Measurement project focusing on the development of an instrument and laboratory capable of realizing and measuring the SI unit of force below

Regenerative Stability Analysis of Highly Interrupted Machining

May 1, 2002
Author(s)
Matthew A. Davies, Jon R. Pratt, Brian S. Dutterer, Timothy J. Burns
We discuss theoretical and experimental work that supports the use of very low radia immersion in the high-speed milling of difficult-to-machine materials, such as titanium alloys. Our theory is based upon modeling the cutting process by a kicked harmonic

Stability Prediction For Low Radial Immersion Milling

May 1, 2002
Author(s)
Matthew A. Davies, Jon R. Pratt, Brian S. Dutterer, Timothy J. Burns
Traditional regenerative stability theory predicts a set of optimally stable spindle speeds at integer fractions of the national frequency of the most flexible mode of the system. The assumptions of this theory become invalid for highly interrupted

NIST Electrostatic Force Balance Experiment

January 1, 2002
Author(s)
John A. Kramar, David B. Newell, Jon R. Pratt
We have designed and built a prototype electrostatic force balance for realizing forces in the micronewton range. The active electrodes are concentric cylinders, the outer serving as the reference and the inner suspended and guided by a rectilinear flexure

SI Traceability of Force at the Nanonewton Level

July 1, 2001
Author(s)
David B. Newell, Jon R. Pratt, John A. Kramar, Douglas T. Smith, L. A. Feeney, Edwin R. Williams
Although nanonewton force measurements are commonplace in industry, no National Measurement Institute supports a link to the International System of Units (SI) below one newton. The National Institute of Standards and Technology has launched a five-year

A New Stable Speed Test Apparatus for Milling

May 1, 2001
Author(s)
J P. Snyder, Jon R. Pratt, Matthew A. Davies, S J. Smith
This paper describes a new device that uses a non-contact force actuator in conjunction with spindle rotation to produce an impulsive periodic driving force on the tool at the tooth passing frequency. Measurements are made of the applied and of the