U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Metrology

Search Publications

Search Title, Abstract, Conference, Citation, Keyword or Author
  • Published Date
Displaying 26 - 50 of 2717

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

Interlaboratory Assessment of Candidate Reference Materials for Lentiviral Vector Copy Number and Integration Site Measurements

April 21, 2025
Author(s)
Hua-Jun He, Zhiyong He, Steven Lund, Barbara Paugh, Jennifer McDaniel, Justin Zook, Sierra Miller, Samantha Maragh, Simona Patange, Mahir Mohiuddin, Alessandro Tona, John Elliott, Kenneth Cole, Sheng Lin-Gibson
Reference materials are essential for accurately measuring integrated lentiviral vector (LV) copy number (VCN) and integration sites for the safety and efficacy of lentivirus-based gene therapy. We conducted an interlaboratory study on NIST candidate

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

Compact Blackbody Radiation Atomic Sensor: Measuring Temperature using Optically Excited Atoms in Vapor Cells

April 17, 2025
Author(s)
David La Mantia, Mingxin Lei, Nikunjkumar Prajapati, Noah Schlossberger, Matthew Simons, Christopher Holloway, Julia Scherschligt, Stephen Eckel, Eric Norrgard
We demonstrate a blackbody radiation thermometer based on optically excited rubidium atoms in a vapor cell. Operating as a calibrated contact thermometer from 308K to 343 K, we realize temperature uncertainty as low as 0.04 %, and statistical temperature

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

BRDF measurements of ultra-black materials with THz quantum cascade lasers

March 19, 2025
Author(s)
Patrick McArdle, Bradley Pelz, Christopher Yung, Nathan Tomlin, John Lehman, Michelle Stephens
In this work we describe the use of a THz quantum cascade laser (QCL) to perform bi-directional reflectance distribution (BRDF) measurements. In particular we are interested in the reflectance properties of ultra-black absorbers for use in detector devices

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
Was this page helpful?