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Metrology

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Displaying 1 - 25 of 5206

Certification of Standard Reference Material(R) 1989 Monodisperse Irregularly Shaped Epoxy-Based Particles (Nominal 100 mm, 150 mm, 220 mm)

May 2, 2025
Author(s)
Srivalli Telikepalli, Dean Ripple, Michael Carrier, Kristen Steffens, David Newton, Christopher Montgomery, Nicholas Ritchie, Anthony Asmar, Michael Halter
Standard Reference Material (SRM) 1989 is a NIST particle standard produced using photolithographic methods and delivers a certified value for particle size of an irregularly shaped particle. This SRM was developed to allow a more accurate monitoring of

CODATA Recommended Values of the Fundamental Physical Constants: 2022

April 30, 2025
Author(s)
Peter Mohr, David Newell, Barry N. Taylor, Eite Tiesinga
We report the 2022 self-consistent values of constants and conversion factors of physics and chemistry recommended by the Committee on Data of the International Science Council (CODATA). The recommended values can also be found at physics.nist.gov

Cannabis Laboratory Quality Assurance Program: Exercise 3 Moisture Final Report

April 28, 2025
Author(s)
Andrea Yarberry, Charles Barber, Laura Wood, Walter Wilson
NIST launched a Cannabis Laboratory Quality Assurance Program (CannaQAP) in 2020 to assist laboratories in demonstrating and improving cannabis (hemp and marijuana) measurement comparability and competence. CannaQAP provided tools that allowed analysts and

Investigating the factors that influence 3D stereo depth sensor noise

April 18, 2025
Author(s)
Terrence Pierce, Prem Rachakonda
3D stereo depth sensors have a variety of applications, including sensing for autonomous vehicles, reverse engineering, and manufacturing automation. The performance of these sensors can be affected by various factors, such as sensor construction, sensor

Investigating the factors that influence 3D stereo depth sensor noise

April 18, 2025
Author(s)
Terrence Pierce, Prem Rachakonda
3D stereo depth sensors have a variety of applications, including sensing for autonomous vehicles, reverse engineering, and manufacturing automation. The performance of these sensors can be affected by various factors, such as sensor construction, sensor

Manipulation of meniscus rise for in situ multiphase nuclear magnetic resonance spectroscopy

April 8, 2025
Author(s)
Veruska Malave, Newell Moser, Edward Garboczi, Mark McLinden, Jason Widegren, Christopher Suiter
Our earlier work demonstrated that nuclear magnetic resonance (NMR) spectroscopy is a viable technique for in situ analysis of vapor–liquid equilibria (VLE) of fluid mixtures and that inserting a capillary into the NMR sample tube allows the simultaneous

Laser Beam Metrology for AM-Bench 2022: Approaches, Results, and Lessons Learned

April 1, 2025
Author(s)
David Deisenroth, Jordan Weaver, Sergey Mekhontsev, Steven Grantham, Shawn P. Moylan
One of key parameters of additive manufacturing by laser powder bed fusion of metal parts (PBF-LB/M) is the power density distribution (PDD) of the process laser beam. This paper describes the methods used to measure the beam PDD, discussing well

A method to calibrate angular positioning errors using a laser tracker and a plane mirror

March 20, 2025
Author(s)
Balasubramanian Muralikrishnan, Katharine Shilling, Vincent Lee, Olga Ridzel, Glenn Holland, John Villarrubia
We describe a method to calibrate angular positioning errors of a rotation stage using a laser tracker (LT), a plane mirror mounted on the stage, and stationary registration nests placed around the stage. Our technique involves determining the direction of

Modulated Laser Thermal Interrogation (MLTI): A Novel In Situ Metal Powder Evaluation Technique for Laser Powder Bed Fusion

March 1, 2025
Author(s)
Sina Ghadi, Xiaobo Chen, Nicholas Tomasello, Nicholas Derimow, Srikanth Rangarajan, Guangwen Zhou, Scott Schiffres
Assessment of metal powders in powder bed additive manufacturing is crucial, as the quality of the powders significantly impacts the final printed parts. This study introduces a novel technique to characterize metal powders by analyzing changes in their

Product ion distributions using H3O+ proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS): mechanisms, transmission effects, and instrument-to-instrument variability

February 27, 2025
Author(s)
Michael Link, Megan Claflin, Christina Cecelski, Ayomide Akande, Delany Kilgour, Paul Heine, Matthew Coggon, Chelsea Stockwell, Andrew Jensen, Jie Yu, Han Huyhn, Jenna Ditto, Carnsten Warneke, William Dresser, Keighan Gemmell, Spiro Jorga, Rileigh Robertson, Joost de Gouw, Timothy Bertram, Jonathan Abbatt, Nadine Borduas-Dedekind, Dustin Poppendieck
Proton-transfer-reaction mass spectrometry (PTR-MS) using hydronium ion (H3O+) ionization is widely used for the measurement of volatile organic compounds (VOCs) both indoors and outdoors. H3O+ ionization, as well as the associated chemistry in an ion

Nanocalorimetry for plasma metrology relevant to semiconductor fabrication

February 4, 2025
Author(s)
John Diulus, Carles Corbella Roca, Feng Yi, David LaVan, Berc Kalanyan, Mark McLean, Lakshmi Ravi Narayan, William Osborn, James Maslar, Andrei Kolmakov
This letter reports on pilot tests of microfabricated nanocalorimeters as a metrology platform for the rapid (sub-100 ms response time) and sensitive detection of neutral radicals generated by reactive cold plasmas, typical in plasma cleaning applications

Insights on grain refinement of Al-Mn-Fe-Si alloy via in situ reaction during laser direct energy deposition

February 2, 2025
Author(s)
Qingyu Pan, Fan Zhang, Deepak Vikraman Pillai, Zilong Zhang, Yufeng Zheng, Lang Yuan, Monica Kapoor, John Carsley, Xiaoyuan Lou
In the present work, we studied the grain refinement by adding in situ reactants, pure titanium (Ti) or a combination of Ti and boron (B), and investigated the governing mechanism in Al-Mn-Fe-Si 3104 alloy made by laser direct energy deposition (DED)

Evaluation of L5 Band GNSS for Use in Time-Transfer

January 27, 2025
Author(s)
Benjamin Pera, Andrew Novick
The L5 frequency band of GPS features a higher power, higher code rate, and superior performance in GNSS denied or degraded environments. GPS L5 is pre-operational at time of writing with 17 satellites but has sufficient coverage for testing and utilizing

Scattering Insights into Shear-Induced Scission of Rodlike Micelles

January 23, 2025
Author(s)
Guan-Rong Huang, Ryan Murphy, Lionel Porcar, Chi-Huan Tung, Changwoo Do, Wei-Ren Chen
Studying the scission of rodlike micelles under mechanical forces is essential for understanding their stability and behavior in industrial applications. Mechanical stress can fragment these micelles, impacting performance. Investigating this process

2024 NIST Summary of U.S. Legal Metrology Activities

January 10, 2025
Author(s)
Juana Williams, John McGuire, Loren Minnich, Gloria Lee, Jan Konijnenburg, Isabel Baucom, Katrice Lippa
The NIST Office of Weights and Measures (OWM) presents its second issue of the 2024 NIST Annual Summary of U.S. Legal Metrology Activities report. This report includes a summary of changes made to NIST Handbook 44 (2024) Specifications, Tolerances and

Checking the Net Contents of Packaged Goods

January 10, 2025
Author(s)
John McGuire, David Sefcik, Loren Minnich, Isabel Baucom, Katrice Lippa
This handbook has been prepared as a procedural guide for the compliance testing of net content statements on packaged goods. Compliance testing of packaged goods is the determination of the conformance results of packaging, distribution, and sale of

Uniform Laws and Regulations in the Areas of Legal Metrology and Fuel Quality

January 10, 2025
Author(s)
John McGuire, David Sefcik, Loren Minnich, Isabel Baucom, Katrice Lippa
This 2025 edition includes amendments made through the Committee on Laws and Regulations of the NCWM with technical guidance from the Office of Weights and Measures (OWM) of the NIST and input from weights and measures officials and industry