Employment of developed integrating sphere photometer system to realize nis secondaryand working standards luminous flux lamps and uncertainty evaluation
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Full Text |
Pdf
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Author |
Manal A. Haridy
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e-ISSN |
1819-6608 |
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On Pages
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1181-1189
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Volume No. |
19
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Issue No. |
18
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Issue Date |
December 14, 2024
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DOI |
https://doi.org/10.59018/092448
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Keywords |
total luminous flux measurements, secondary and working standard lamps, developed integrating sphere photometer, uncertainty.
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Abstract
In the present research, the developed NIS integrating sphere photometer system was used to determine the total luminous flux and the ratio of the measuring values obtained by the integrating sphere photometer to the certified values for both NIS secondary and working standard lamps in the present study. The 2.5-m integrating sphere in the National Institute of Standards was equipped with the NIS photometer, LMT U1000, and a group of secondary standard lamps previously calibrated at the National Physical Laboratory, England. These were used to measure the total luminous flux of the NIS working standard lamps. A second arrangement for the measurement of the SPD of lamps included the NIS spectroradiometer (Ocean Optics HR 2000) and a photometric bench. The calculation of the spectral mismatch correction factor was required as well as the estimation of the uncertainty of that factor. Comparison of the Integrating sphere photometer measurements with the certified values for NIS secondary standard lamps showed results that differ from 0.0029 to 0.004, while it was found to vary between 0.0019 and 0.0055 for the NIS working standard lamps. The expanded uncertainty of the total luminous flux measurements was estimated at 1.49%, considering all the uncertainties in the determination of the luminous flux unit realization besides other factors. This comprehensive approach is effectively permitting the accurate measurement and calibration of luminous flux standards at NIS.
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