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https://www.nist.gov/people/jon-r-pratt
Jon R. Pratt (Fed)
Dr. Pratt is a mechanical engineer and Chief of the Quantum Measurement Division of the Physical Measurement Laboratory (PML) at the National Institute of Standards and Technology (NIST).
Leon S. Chao, Rafael Marangoni, Frank C. Seifert, Darine El Haddad, Jon R. Pratt, David B. Newell, Stephan Schlamminger
After the recent redefinition of the International System of Units (SI), torque no longer needs to be traceable to a calibrated mass in a gravitational field
Stephan Schlamminger, Harald Bosse, Horst Kunzmann, Jon R. Pratt, Ian Robinson, Michael de Podesta, Paul Shore, Paul Morantz
All measurements performed in science and industry are based on the International System of Units, the SI. It has been proposed to revise the SI following an
Darine El Haddad, Frank Seifert, Leon Chao, Antonio Possolo, David B. Newell, Jon R. Pratt, Carl J. Williams, Stephan Schlamminger
Researchers at the National Institute of Standards and Technology(NIST) estimate the value of the Planck constant as h = 6.62606994(10) x 10^-34 Js, hence with
Darine El Haddad, Frank C. Seifert, Leon S. Chao, Shisong Lee, David B. Newell, Jon R. Pratt, Carl J. Williams, Stephan Schlamminger
Using a watt balance and a frequency comb, a mass-energy equivalence is derived. The watt balance compares mechanical power measured in terms of the meter, the
The present invention features a micrometer-scale torsion balance device comprising a rigid mass and two or more nanoribbons attached to the rigid mass. The rigid mass may be suspended by the two or more nanoribbons. The two or more nanoribbons may be placed under tensile stress. A local
An absolute mass balance determines an absolute mass of an object and includes: a dual diameter wheel including: a balance fulcrum; and a balance beam disposed on the balance fulcrum and including: a main mass arm and a counter mass arm; a main mass receiver that receives the object; a main magnet
An optomechanical gravimeter includes: a first and second accelerometer; and a spacer member interposed between the first accelerometer and the second accelerometer such that the first accelerometer and the second accelerometer independently include: a basal member; a test mass disposed on the basal