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Search Publications by: Thomas C Larason (Fed)

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Displaying 1 - 25 of 53

NIST Traveling Tunable Laser Projector (TTLP) for UV-Blue Disinfection Dose Determinations

June 21, 2022
Thomas C. Larason, Steven Grantham, Clarence Zarobila, Yuqin Zong, C Cameron Miller, Michael Schuit, Brian Holland, Stewart Wood, Melissa Krause
As COVID-19 was overtaking the world in the spring of 2020, the National Institute of Standards and Technology began collaborating with the National Biodefense Analysis and Countermeasures Center to study the inactivation of SARS-CoV-2 to different UV and

The Irradiance Instrument Subsystem (IRIS) on the Airborne-Lunar Spectral Irradiance (Air-LUSI) Instrument

March 23, 2022
Steven Grantham, Thomas C. Larason, Clarence Zarobila, Stephen Maxwell, John Woodward, Kevin Turpie, S. Andrew Gadsden
The objective of the airborne LUnar Spectral Irradiance (air-LUSI) project is to make low uncertainty, SI-traceable measurements of the lunar spectral irradiance in the visible to near-infrared (VNIR) region from an aircraft above most of the optically

Optical and Mechanical Design of a Telescope for Lunar Spectral Irradiance Measurements from a High-Altitude Aircraft

September 8, 2020
Clarence Zarobila, Steven Grantham, Steven W. Brown, John T. Woodward IV, Stephen Maxwell, Dana R. Defibaugh, Thomas C. Larason, Kevin Turpie
We have designed a non-imaging telescope for measurement of the spectral irradiance of the moon. The telescope was integrated into a wing pod of a NASA ER-2 research aircraft to measure lunar spectral irradiance during flight. The telescope and support


June 14, 2019
Carl C. Miller, Thomas C. Larason, Dianne L. Poster, Yaw S. Obeng, Mike Postek, Richard Martinello
Nationwide, healthcare-associated infections (HAIs) infect one in every 25 hospital patients, account for more than 99,000 deaths and increase medical costs by more than $35 billion, each year. Ultraviolet-C (UV-C) antimicrobial devices are shown to reduce

Gain Calibration of Current-to-Voltage Converters

November 19, 2018
Thomas C. Larason, Carl C. Miller
Current-to-voltage converters are used in many photometric and radiometric applications. The calibration of current- to-voltage converters at a few input currents is not always sufficient to understand the linearity and the bias of a device. Many devices

Calibration of night vision goggles: an SI-units-based measurement technique

July 11, 2017
Vyacheslav B. Podobedov, George P. Eppeldauer, Thomas C. Larason
A new night vision goggles (NVG) gain definition for the calibration process is proposed and evaluated. This definition is based on the radiance measurements at the input and output of the NVG. In contrast to the old definition which uses a non-

Calibration of spectral responsivity of IR detectors in the range from 0.6 mm to 24 mm

June 15, 2017
Vyacheslav B. Podobedov, George P. Eppeldauer, Leonard M. Hanssen, Thomas C. Larason
We report the upgraded performance of the National Institute of Standards and Technology (NIST) facility for spectral responsivity calibrations of infrared (IR) detectors in both radiant power and irradiance measurement modes. The extension of the

Calibration procedure for UV-365 integrated irradiance measurements

September 8, 2015
George P. Eppeldauer, Thomas C. Larason, Robert E. Vest, Uwe Arp, Howard W. Yoon
Since the CIE standardized rectangular-shape spectral response function for the 320 nm to 400 nm wavelength range can be realized only with large spectral mismatch, the realized UV-A meters have different response functions resulting in large errors in

Standardization of UV LED measurements

September 8, 2015
George P. Eppeldauer, Thomas C. Larason, Howard W. Yoon
Traditionally used source spectral-distribution or detector spectral-response based standards cannot be applied for accurate UV LED measurements. Since the CIE standardized rectangular-shape spectral response function for UV measurements cannot be realized

New night vision goggle gain definition

May 12, 2015
Vyacheslav B. Podobedov, George P. Eppeldauer, Thomas C. Larason
A new definition is proposed for the calibration of Night Vision Goggle (NVG) gains. This definition is based on the measurement of radiometric input and output quantities of the NVG. While the old definition used the “equivalent fL” which is a non SI

IR-enhanced Si reference detectors for 1-step scale transfers from 300 nm to 1000 nm

November 20, 2014
George P. Eppeldauer, Thomas C. Larason, Jeanne M. Houston, Robert E. Vest, Uwe Arp, Howard W. Yoon
IR-enhanced Si photodiodes have improved radiometric and electronic characteristics as compared to other widely used Si photodiodes and can be used as responsivity standards in the wavelength range from 300 nm to 1000 nm. Their low predicted uncertainty

Wavelength Dependent UV Inactivation and DNA Damage of Adenovirus 2 as Measured by Cell Culture Infectivity and Long Range Quantitative PCR

November 22, 2013
Sara E. Beck, Roberto A. Rodriguez, Karl G. Linden, Thomas M. Hargy, Thomas C. Larason, Harold B. Wright
Adenovirus is regarded as the most resistant pathogen to ultraviolet (UV) disinfection due to its demonstrated resistance to monochromatic, low-pressure (LP) UV irradiation at 254 nm. This resistance has resulted in high UV dose requirements for all

Measuring the UV Action Spectra of Pathogens and Surrogates

September 22, 2013
Karl G. Linden, Harold B. Wright, Sara E. Beck, Thomas M. Hargy, Thomas C. Larason, Randi M. McCuin
The use of bioassays to determine reduction equivalent doses delivered by UV reactors is recognized as an effective measure of UV disinfection systems. Low pressure (LP) UV delivered in controlled collimated beam systems provides dose response curves which

Using a Tunable Ultraviolet Laser for the Inactivation of Water Pathogens

September 22, 2013
Thomas C. Larason, Keith R. Lykke, Ping-Shine Shaw, Lin Chungsan
Ultraviolet (UV) radiation effectively inactivates common pathogens found in ground and surface waters such as Cryptosporidium, Giardia, and most bacterial pathogens (e.g. E. coli). Water treatment facilities are now using UV radiation for disinfection of

Extension of the NIST spectral power-responsivity calibration service to 2500 nm

March 2, 2012
George P. Eppeldauer, Howard W. Yoon, Jinan Zeng, Thomas C. Larason, Jeanne M. Houston, Vladimir Khromchenko
The National Institute of Standards and Technology (NIST) is working to extend the upper wavelength limit of the spectral power-responsivity calibration service from 1800 nm to 2500 nm. This extension is based on extended-InGaAs (EIGA) transfer- and

Calibrations of Current-to-Voltage Transimpedance Amplifiers Using Electrical Standards

June 13, 2010
Howard W. Yoon, George P. Eppeldauer, Dean G. Jarrett, Thomas C. Larason, Wan-Seop Kim
For photocurrent measurements with low uncertainties, a wide-dynamic range current-to-voltage converter traceable to resistance standards has been developed at the NIST. The design and calibration of the converter standard are described. For validation

Report on the Key Comparison CCPR K2.a-2003

October 30, 2009
Yoshihiro Ohno, Steven W. Brown, Thomas C. Larason
Under the framework of Mutual Recognition Arrangement (MRA) for national measurements standards and for calibration and measurement certificates issued by National Metrology Institutes (NMIs) signed in 1999, an international comparison of spectral