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NRC-NIST intercomparison of calibration systems for current transducers with a voltage output at power frequencies

E. So, R. Arseneau, D. Bennett, T.L. Nelson, B.C. Waltrip
2003 IEEE Transactions on Instrumentation and Measurement  
The results indicate that there are no'significant differences in the overall accuracy of calibration systems for current transducers with a voltage output at power frequencies in each laboratory.  ...  A number of international comparisons of current transformer calibrations at power frequencies were conducted in the past. However, all comparisons were done with a secondary current output of 5 A.  ...  The comparison of the two systems at a power frequency of 60 Hz for calibrations of current transducers at a current range of 100 A with a corresponding output voltage range of 10 V is presented.  ... 
doi:10.1109/tim.2003.809909 fatcat:j3f6giz5yrdvthrjf4cn7cw3ju

The current status of measurement standards for acoustics and vibration at INMETRO

Gustavo P. Ripper, Walter E. Hoffmann
2002 Journal of the Acoustical Society of America  
These laboratories are responsible for the establishment, validation and maintenance of the Brazilian national measurement standards used for the realization of the units of the International System of  ...  This paper outlines the current status of these measurement standards and presents the measurement capabilities of INMETRO in the field of acoustics and vibration.  ...  Two supplementary intercomparisons among NIST, INMETRO and CENAM extended the frequency range of the interferometric calibration of accelerometers to 10 kHz and allowed the evaluation of the gain calibration  ... 
doi:10.1121/1.4779460 fatcat:yk6nwduzefdormuc7mc3ddn7nm

News briefs

1990 Journal of Research of the National Institute of Standards and Technology  
The amplifier provides a stable output current up to 35 A rms at 100 kHz with an output compliance voltage of 5 V rms. The 3-dB bandwidth is 1 MHz, and the gain instability is less than ± 10 ppm/min.  ...  HIGH-CURRENT, WIDEBAND TRANS-CONDUCTANCE AMPLIFIER DEVELOPED To meet an increasing number of requests to NIST for a variety of calibrations at higher currents and higher frequencies than were previously  ...  NIST TEST SYSTEM PROVIDES NEW CAPABILITIES FOR NONDESTRUCTIVE EVALUATION OF POWER TRANSISTORS A new NIST nondestructive test system for power transistors that can accommodate up to 100 A and switch up  ... 
doi:10.6028/jres.095.0010 fatcat:q4xtye4zi5crtfzof2rltww3ba

Doppler-Free Two-Photon Cavity Ring-Down Spectroscopy of a Nitrous Oxide (N_2O) Vibrational Overtone Transition [article]

Gang Zhao, D. Michelle Bailey, Adam J. Fleisher, Joseph T. Hodges, and Kevin K. Lehmann
2020 arXiv   pre-print
At a sample pressure of p = 0.13 kPa, we report a large two-photon cross-section of σ_13^(2) = 8.0 × 10^-41 cm^4 s molecule^-1 for the Q(18) rovibrational transition at a resonant frequency of ν_0 = 66179400.8  ...  High power was achieved by optical self-locking of a quantum cascade laser to a linear resonator of finesse F = 22730, and accurate laser detuning over a 400 MHz range was measured relative to an optical  ...  Cecelski (NIST) and Jennifer Carney (NIST) for the loan of a certified gas sample of N2O-in-air. Hélène M. Fleurbaey (NIST) commented on the manuscript.  ... 
arXiv:2003.12624v1 fatcat:oa6j7rf57fbzhi5kieqdtuuame

Doppler-Free Two-Photon Cavity Ring-Down Spectroscopy of a Nitrous Oxide (N2O) Vibrational Overtone Transition

Gang Zhao, D Michelle Bailey, Adam J Fleisher, Joseph T Hodges, Kevin K Lehmann
2020 Physical Review A  
At a sample pressure of p = 0.13 kPa, we report a large two-photon cross-section per molecule of σ 13 ( 2 ) = 8.0 × 10 - 41 cm4 s for the Q(18) rovibrational transition at a resonant frequency of ν 0 =  ...  High power was achieved by optical self-locking of a quantum cascade laser to a linear resonator of finesse F = 22730 , and accurate laser detuning over a 400 MHz range was measured relative to an optical  ...  Cecelski (NIST) and Jennifer Carney (NIST) for the loan of a certified gas sample of N 2 O-in-air. Hélène M. Fleurbaey (NIST) commented on the manuscript.  ... 
pmid:33103022 pmcid:PMC7580019 fatcat:cjrk24jeabhtromq5ifmvkn6vu

News briefs

1994 Journal of Research of the National Institute of Standards and Technology  
With this system, optical power meters can be calibrated both at a particular source wavelength or over the range of wavelengths of the tunable laser diode.  ...  PAPER DETAILS CALIBRATION SYSTEM FOR POWER METERS Using tunable laser diodes, NIST has developed a new method to calibrate optical power meters, the most common type of test equipment used in the optical  ... 
doi:10.6028/jres.099.056 fatcat:rt6xacxtofbengbbb56sj7jriy

News Briefs

1998 Journal of Research of the National Institute of Standards and Technology  
ACTIVE AC VOLTAGE DIVIDER EXTENDS RANGE FOR PRIMARY ELECTRIC POWER CALIBRATIONS A special-purpose ac voltage divider system has been developed by researchers at NIST to meet the demand for power and energy  ...  Fiber-Optic Current Transformer-a signal-sensing device with a two-part transduction mechanism to measure current in high-voltage power lines.  ...  The added material includes a check list for reviewing the consistency of written documents with the SI.  ... 
doi:10.6028/jres.103.018 fatcat:wmzv4vjaznhpxdg5hya7wquywy

Ultrasensitive spectroscopy, the ultrastable lasers, the ultrafast lasers, and the seriously nonlinear fiber: a new alliance for physics and metrology

J.L. Hall, Jun Ye, S.A. Diddams, Long-Sheng Ma, S.T. Cundiff, D.J. Jones
2001 IEEE Journal of Quantum Electronics  
For brevity, we here focus mainly on the new possibilities in the field of optical frequency measurement.  ...  Cundiff are with JILA,  ...  A suitable description of this RF/optical clockworks system may be to say it is "Self-Calibrating."  ... 
doi:10.1109/3.970893 fatcat:kkbor54ff5gbrgrbnzmzdvl7ei

The NIST length scale interferometer

John S. Beers, William B. Penzes
1999 Journal of Research of the National Institute of Standards and Technology  
The National Institute of Standards and Technology (NIST) interferometer for measuring graduated length scales has been in use since 1965.  ...  A continuous program of modernization by making physical modifications, measurement procedure changes and computational revisions is described, and the effects of these changes are evaluated.  ...  Beers is a physicist and Guest Researcher in the Precision  ... 
doi:10.6028/jres.104.017 fatcat:herkil7vdne23lq5ujol35hgdy

Optical frequency synthesis based on mode-locked lasers

Steven T. Cundiff, Jun Ye, John L. Hall
2001 Review of Scientific Instruments  
The synthesis of optical frequencies from the primary cesium microwave standard has traditionally been a difficult problem due to the large disparity in frequency.  ...  This review article describes how mode-locked lasers are used for optical frequency synthesis and gives recent results obtained using them.  ...  ACKNOWLEDGMENTS The authors wish to acknowledge the contributions of the many individuals who have contributed to this work. In  ... 
doi:10.1063/1.1400144 fatcat:rur7mevfvng5feldehympq6bxe

A unique way of sound production in the snapping shrimp (Alpheus heterochaelis)

Barbara Schmitz, Michel Versluis, Anna von der Heydt, Detlef Lohse
2000 Journal of the Acoustical Society of America  
The Electroacoustic radiation conductance, defined as the ratio of the ultrasonic power of a transducer and the square of the rf voltage at its input, was calculated from the recorded data.  ...  Outputs of an electronic balance and the excitation voltage were simultaneously sampled and recorded.  ...  The measurement system was a calibrated vertical array 14-18 km from a known geological feature.  ... 
doi:10.1121/1.4743419 fatcat:g5t436uevvdzfdqfenskbzrgla

Neural network modeling of a dolphin's sonar discrimination capabilities

Lars N. Andersen, A. René Rasmussen, Whitlow W. L. Au, Paul E. Nachtigall, Herbert Roitblat
1994 Journal of the Acoustical Society of America  
The sound field scattered by a smooth thin elastic shell immersed in fluid arises largely from specular reflection and acoustic-membrane coupling, unless both source and observer are located near or on  ...  For this task, CENAM staff has relied on the technical assistance of the corresponding groups at NIST and NRC.  ...  The method replaces the insert-voltage calibration technique which is frequently used with large or unmanned systems.  ... 
doi:10.1121/1.410770 fatcat:ioiiov6bmjdi7kiflait5dhdfe

Neural network modeling of a dolphin's sonar discrimination capabilities

Whitlow W. L. Au, Lars N. Andersen, A. René Rasmussen, Herbert L. Roitblat, Paul E. Nachtigall
1995 Journal of the Acoustical Society of America  
The sound field scattered by a smooth thin elastic shell immersed in fluid arises largely from specular reflection and acoustic-membrane coupling, unless both source and observer are located near or on  ...  For this task, CENAM staff has relied on the technical assistance of the corresponding groups at NIST and NRC.  ...  The method replaces the insert-voltage calibration technique which is frequently used with large or unmanned systems.  ... 
doi:10.1121/1.413700 pmid:7608403 fatcat:m3nunzs4wfflhfl27n4shdn2n4

A Model for Online Interactive Remote Education for Medical Physics Using the Internet

Milton K Woo, Kwan-Hoong Ng
2003 Journal of Medical Internet Research  
region, with I and V the chamber current and voltage, respectively.  ...  There is also a need for two particular beams for general diagnostic chamber calibrations to be established at NIST.  ...  It consists of a detector system with an active surface that is 20.3 cm by 25.4 cm connected by a cable to a computer which controls the electronics during acquisition, processing, and display.  ... 
doi:10.2196/jmir.5.1.e3 pmid:12746208 pmcid:PMC1550549 fatcat:tsyf45yusza2jiglkq62rgo3qm

Influence of statistical surface models on dynamic scattering of high‐frequency signals from the ocean surface

Christian Bjerrum‐Niese, Leif Bjo/rno/
1994 Journal of the Acoustical Society of America  
The sound field scattered by a smooth thin elastic shell immersed in fluid arises largely from specular reflection and acoustic-membrane coupling, unless both source and observer are located near or on  ...  For this task, CENAM staff has relied on the technical assistance of the corresponding groups at NIST and NRC.  ...  The method replaces the insert-voltage calibration technique which is frequently used with large or unmanned systems.  ... 
doi:10.1121/1.411137 fatcat:ajwj7bozxzg6fd27v4xe57drgm
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