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Tina Butcher, Richard A. Harshman, Gloria Lee, Juana Williams, Jan Konijnenburg, Lisa Warfield, Katrice Lippa, Shelby Bowers, Elizabeth Benham
NIST Handbook 44 includes specifications, tolerances, and other technical requirements for weighing and measuring devices. These requirements are intended to encourage the design, installation, testing, and use of weighing and measuring devices that
Andrew Novick, Michael A. Lombardi, Demetrios Matsakis, John Clark
GPS-disciplined clocks (GPSDCs) are designed to optimize the accuracy and stability of their pulse-per-second (PPS) and frequency outputs by steering an internal oscillator to the timing solution from a GPS receiver based on the received satellite signals
The pixel is often used as a unit of measurement in information technology. Unfortunately, there is not a simple, consistently-applicable answer to what it is a measure of. This report analyzes the pixel unit through the lens of metrology and shows how one
Continuity is usually assumed as a defining feature of measured quantities. This premise is false for counted quantities, amount of substance, electric charge, and others that are constrained to exist in integral multiples of a quantum. A software
Richard Essex, Jacqueline L. Mann, Denis E. Bergeron, Ryan P. Fitzgerald, Svetlana Nour, Gordon A. Shaw, R. Michael Verkouteren
Isotope dilution mass spectrometry was used to independently assess the accuracy of mass measurement methods developed to quantitatively dispense milligram quantities of aqueous solution. Solutions of isotopically enriched 158Gd and enriched 155Gd were
Daniel Barker, Bishnu Acharya, James A. Fedchak, Nikolai Klimov, Eric Norrgard, Julia Scherschligt, Eite Tiesinga, Stephen Eckel
We describe the cold-atom vacuum standards (CAVS) under development at the National Institute of Standards and Technology. The CAVS measures pressure in the ultra-high and extreme-high vacuum regimes by measuring the loss rate of sub-millikelvin sensor
Derek Huang, Anthony Kotula, Chad R. Snyder, Kalman Migler
Motivated by the problem of brittle mechanical behavior in recycled blends of high density polyethylene (HDPE) and isotactic polypropylene (iPP), we employ optical microscopy, rheo-Raman, and differential scanning calorimetry (DSC) to measure the
Stephan Schlamminger, Leon Chao, Vincent Lee, David B. Newell, Clive Speake
With the torsion balance developed at the Bureau International des Poids et Mesures (BIPM), the Newtonian constant of gravitation, $G$, can be measured with two methods. In the Cavendish method, the external gravitational torque is obtained from the
Johanna Camara, Jeanita Pritchett, Yasmine Daniels, Mary Bedner, Michael Nelson, Mark Lowenthal, Zia Fazili, Christine Pfeiffer, Karen W. Phinney, Katherine E. Sharpless, Lane C. Sander, Katrice Lippa, James H. Yen, Adam Kuszak, Stephen Wise
The US National Institute of Standards and Technology (NIST) developed a Standard Reference Material® (SRM®) 3949 Folate Vitamers in Frozen Human Serum to replace SRM 1955 Homocysteine and Folate in Human Serum. The presence of increased endogenous levels
John D. Wright, Aaron Johnson, Michael R. Moldover, Shin-ichi Nakao
We review diverse types of gas flow standards that are used to calibrate other gas flow meters. For each type of standard, we describe the principles of its operation and at least one hardware example. We identify the practical limits of the example's
Linli Meng, Alireza Panna, Swapnil Mhatre, Albert Rigosi, Shamith Payagala, Dipanjan Saha, Ngoc Thanh Mai Tran, Ching-Chen Yeh, Randolph Elmquist, Angela R. Hight Walker, Dean G. Jarrett, David B. Newell, Yanfei Yang
Chuck Barber, Colleen E. Bryan Sallee, Carolyn Burdette, Shaun Kotoski, Melissa M. Phillips, Walter Brent Wilson, Laura Wood
In 2020, NIST launched Cannabis Laboratory Quality Assurance Program (CannaQAP) to improve the comparability of the analytical measurements of cannabis and cannabis-derived products in forensic and cannabis (hemp and marijuana) testing laboratories
Dimitrios Georgakopoulos, Ilya Budovsky, Samuel P. Benz
Josephson voltage standards (JVSs) provide a primary realization of the volt, the unit of electromotive force. They generate direct (dc) voltages up to 10 V and show agreement better than 1 nV/V at 10 V. For JVSs based on the sinusoidal [or continuous-wave
Vincent Lee, Stephan Schlamminger, Leon Chao, David B. Newell, Jon Pratt, Craig Shakarji, Clive Speake
This paper discusses the dimensional metrology challenges encountered while performing G measurements using the BIPM torsion balance and our solutions.
There remains a need for rheological characterization of metal powder used for powder-spreading-based additive manufacturing (AM). Novel powder rheometers introduced to the commercial market for this purpose must be rigorously evaluated for repeatability
Takehiko Oe, Shamith Payagala, Alireza Panna, S. Takada, N. Kaneko, Dean G. Jarrett
A precise high resistance comparison was performed between the traveling dual source bridge developed by the National Metrology Institute of Japan (NMIJ) and the Adapted Wheatstone Bridge of the National Institute of Standards and Technology (NIST) from 10
The metrological definition of traceability for a GPSDO or GPSDC requires an unbroken series of measurements to a national standard, with known uncertainties at each step. The calibrations must be end-to-end, including the antenna and cabling. While
Stephan Schlamminger, Lorenz Keck, Frank Seifert, Leon Chao, Darine El Haddad, Shisong Li
Analytically the force and torques on a coil in a field of magnetic flux density can be calculated one of two ways. The line integral can be conducted along the coil's wire, summing up the differential force contribution. For each differential line segment
David Sefcik, Katrice Lippa, N. Alan Heckert, Stephen Benjamin, Ivan Hankins, Don Onwiler
The National Conference on Weights and Measures (NCWM) in partnership and cooperation with the NIST Office of Weights and Measures (OWM) and the Weights and Measures Divisions of select U.S. States initiated the 2022 National Survey on 20 lb LPG (Propane)
Kaleb Duelge, George Mulholland, Vincent A. Hackley, Michael Zachariah
A critical and extensive comparison was made between differential mobility analysis (DMA) measurements of the mean diameter of monodisperse gold nanoparticles (AuNP), based on step-voltage mode and the more commonly used scan-voltage mode (commercially
Lorenz Keck, Frank Seifert, David B. Newell, Rene Theska, Darine El Haddad
A quantum electro-mechanical metrology suite (QEMMS) is being built at the National Institute of Standards and Technology (NIST). As the first instrument in his class, the QEMMS combines all three, a programmable Josephson voltage system, a quantum Hall
Linsey Rodenbach, Alireza Panna, Shamith Payagala, Ilan Rosen, Molly Andersen, Joseph Hagmann, Peng Zhang, Lixuan Tai, Kang Wang, Dean G. Jarrett, Randolph Elmquist, Jason Underwood, David B. Newell, David Goldhaber-Gordon, Albert Rigosi
Catherine Cooksey, James A. Fedchak, Robert Hanisch, Gregory (Greg) C. Cala, Damian Lauria, Raymond Plante, Benjamin Long, John S. Quintavalle, Manmohan Moodra
Early in 2022 NIST embarked on a pilot project to produce digital calibration reports and certificates of analysis for reference materials. The goal of the project was to produce a few examples of each for the purpose of assessing the scope and challenges