The NIST detector-based luminous intensity scale
نویسندگان
چکیده
منابع مشابه
The NIST Detector-Based Luminous Intensity Scale
The Système International des Unités (SI) base unit for photometry, the candela, has been realized by using absolute detectors rather than absolute sources. This change in method permits luminous intensity calibrations of standard lamps to be carried out with a relative expanded uncertainty (coverage factor k = 2, and thus a 2 standard deviation estimate) of 0.46 %, almost a factor-of-two impro...
متن کاملThe Detector-Based Candela Scale and Related Photometric Calibration Procedures at NIST
The candela, one of the SI base units, has been realized by using absolutely calibrated detectors rather than sources. A group of eight photometers was constructed using silicon photodiodes, precision apertures, and glass filters for V (λ) match. Their absolute spectral responsivities were calibrated against the NIST absolute spectral responsivity scale. The measurement chain has been significa...
متن کاملRealization of NIST 1995 Luminous Flux Scale using Integrating Sphere Method
A new NIST luminous flux scale has been realized using the integrating sphere method, on which theoretical and experimental studies were previously conducted and reported. The NIST 2 m integrating sphere was modified to add an opening and an additional baffle to apply this method. Flux from an external source (1000 W quartz halogen lamp) is introduced into the sphere through a limiting aperture...
متن کاملThe NIST Length Scale Interferometer
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001 The National Institute of Standards and Technology (NIST) interferometer for measuring graduated length scales has been in use since 1965. It was developed in response to the redefinition of the meter in 1960 from the prototype platinum-iridium bar to the wavelength of light. The history of the interferometer is recalle...
متن کاملErratum: The NIST Length Scale Interferometer
[This corrects the article on p. 225 in vol. 104.].
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ژورنال
عنوان ژورنال: Journal of Research of the National Institute of Standards and Technology
سال: 1996
ISSN: 1044-677X
DOI: 10.6028/jres.101.014