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Dean G. Jarrett, J. A. Marshall, T. A. Marshall, Ronald F. Dziuba
The design and testing of a low thermal electromotive force guarded scanner, developed to provide completely guarded switching when used with actively guarded resistance bridge networks, is described. The design provides a continuous guard circuit trace on
Samuel Benz, Charles J. Burroughs, Todd E. Harvey, Clark A. Hamilton
We have developed an accurate ac and dc bipolar voltage source based on the quantized pulses of Josephson junctions. A factor-of-6 increase in output voltage over previous unipolar waveforms is achieved by generating bipolar waveforms where arrays of
Samuel Benz, Clark A. Hamilton, Charles J. Burroughs
Operating margins for biolar superconducting voltage waveform synthesizer were measured. Current ranges were determined for 101 equally spaced dc voltage steps between - 18.6 and + 18.6 mV. The measured voltages of these steps deviated from the expected
We present design criteria for arrays of Josephson junctions optimized for use in the Josephson digital-analog converter and for a THz oscillator. We will briefly analyze existing high temperature superconducting Josephson junction processes and describe
Richard L. Steiner, David B. Newell, Edwin R. Williams
An improved determination of the ratio of power, measured in terms of the Josephson and quantum Hall effects, and also the meter, kilogram, and second, has been completed. The result is expressed as: W 90/W = 1 + (8187) x 10 -9. This is an order of
Ronald F. Dziuba, Dean G. Jarrett, L. L. Scott, Andrew J. Secula
The National Institute of Standards and Technology (NIST) has fabricated stable, transportable 10 MΩ} and 1 GΩ} standard resistors for use in an international comparison of high resistances. This fabrication process is being applied to the construction of
The calculable capacitor at National Institute of Standards and Technology (NIST) links the U.S. capacitance unit to the SI unit and has a relative standard uncertainty of 2 x 10 -8. Geometrical imperfections are one of the largest sources of this
David B. Newell, Richard L. Steiner, Edwin R. Williams
The last remaining SI base unit defined by an artifact is the kilogram. The NIST watt balance has been designed to measure the ratio of mechanical to electrical power, linking the artifact kilogram, the meter, and the second to the practical realizations
In all experiments reported to date the measurement values of the ac quantized Hall resistances R H varied with the applied current frequency, and differed significantly from the dc values of R H, making it difficult to use the ac quantum Hall effect as an
Marvin E. Cage, Anne-Marie Jeffery, Randolph Elmquist, Kevin C. Lee
Many ac quantized Hall resistance experiments have measured significant values of ac longitudinal resistances under temperature and magnetic field conditions in which the dc longitudinal resistance values were negligible. We investigate the effect of non
Abstract: The National Institute of Standards and Technology operates a number of research projects to advance measurement science and technology for the microelectronic industries. We report here on one component of the NIST program, the fundamental
David B. Newell, Richard L. Steiner, Edwin R. Williams, Alain Picard
Reduction in the total uncertainty of the NIST Watt Balance is limited by the present configuration of the experiment. Most of the major relative uncertainty components arise from the fact that the experiment is performed in air. To reduce the contribution
We report on several previous and ongoing investigations into the source of, and the amelioration of, the charge offset noise in SET (single-electron tunneling) transistors, made of Al/AlOx/Al tunnel junctions. Previous work has shown that significant time
Joseph R. Kinard Jr., Thomas E. Lipe Jr., Clifton B. Childers, S. Avramov
High-voltage thermal converters (HVTCs) are used as standards of ac-dc difference and for the measurement and calibration of ac voltage up to 1000 V and 100 kHz. Their multiplying resistors can be compensated to yield small ac-dc differences by using
Richard L. Steiner, David B. Newell, Edwin R. Williams
The present NIST Watt Balance has a relative combined standard uncertainty of about 145 nW/W. The final results of this phase of the experiment are presented. Improvements in the Type B (nonstatistical) uncertainty contributions, along with several
Ronald F. Dziuba, Dean G. Jarrett, L. L. Scott, Andrew J. Secula
The National Institute of Standards and Technology (NIST) has fabricated stable, transportable 10 MΩ} and 1 GΩ} standard resistors for use in an international comparison of high resistances. This fabrication process is being applied to the construction of
The 10 kilohm measurement system at the National Institute of Standards and Technology has been improved. The guarded resistance bridge is based on the Warshawsky bridge model and is self-balancing through the use of a precision feedback system. A unique
Thomas E. Lipe Jr., Joseph R. Kinard Jr., Clifton B. Childers
This paper describes recent developments in the ac-dc difference calibration service for thermal transfer standards at the National Institute of Standards and Technology. Related developments include the revision of calibration uncertainties, with
The National Institute of Standards and Technology (NIST) offers resistance Measurement Assurance Program (MAP) transfers at the 1 ohm} and 10 kohm} levels, to provide a method of assessing and maintaining the quality of a customer's measurement process
Marvin E. Cage, Anne-Marie Jeffery, Randolph Elmquist
We find from equivalent circuit calculations that a single ac ratio bridge could be used to measure the ac quantized Hall resistance and to also provide independent values of the ac longitudinal resistance in a quantum Hall effect device by making