New standards at NIST based on digital techniques.
نویسندگان
چکیده
منابع مشابه
Standards for Waveform Metrology Based on Digital Techniques
Over the last decade the use of digital synthesis and sampling techniques for generating and measuring electrical waveforms has increased dramatically with the availability of improved digital-to-analog (D/A) and analog-to-digital (A/D) converters and related devices. With this evolution has come the need for physical laboratory standards and test methods to support the performance specificatio...
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The development of atomic frequency standards at NIST is discussed and three of the key frequency-standard technologies of the current era are described. For each of these technologies, the most recent NIST implementation of the particular type of standard is described in greater detail. The best relative standard uncertainty achieved to date for a NIST frequency standard is 1.5×10(-15). The un...
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This document describes the procedures used at NIST to calibrate dc voltage standards in terms of the NIST volt. Three calibration services are offered by the Electricity Division: Regular Calibration Service (RCS) of client standard cells at NIST; the Volt Transfer Program (VTP) a process to determine the difference between the NIST volt and the volt as maintained by a group of standard cells ...
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A spectrophotometer system for spectral characterization of materials in the infrared has been built around a bench-top Fourier transform instrument. Its capabilities include the measurement of directional-hemispherical re ̄ectance from 1 to 18 mm. The spectral re ̄ectance measurement is performed with an integrating sphere with an incidence angle of 88. Both relative and absolute measurements ca...
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NIST has recently established a detector-based luminous intensity unit (candela, cd), which is derived from the NIST absolute cryogenic radiometer. Subsequently, the luminous flux unit (lumen, lm) and the luminance unit (cd/m2) have been established based on the detector-based candela, and now all the NIST photometric units are tied to the cryogenic radiometer. The illuminance unit is realized ...
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ژورنال
عنوان ژورنال: The Journal of the Acoustical Society of America
سال: 1992
ISSN: 0001-4966
DOI: 10.1121/1.403373