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Certified Transmittance Density Uncertainties for Standard Reference Materials using a Transfer Spectrophotometer



John C. Travis, Melody V. Smith, Steven J. Choquette, Hung-Kung Liu


Overall uncertainties are evaluated for the certification of transmittance density (absorbance referred to air) and regular spectral transmittance for solid neutral density filter Standard Reference Materials by means of a transfer spectrophotometer. Traceability is asserted by means of comparison measurements to a recognized reference spectrophotometer. The uncertainties are evaluated without bias correction, using the combination of the legacy combined standard uncertainty values with uncertainty components for the measured bias, the standard uncertainty of this measured bias, and the standard uncertainty characteristic of simple replication for a single measurement using the transfer spectrophotometer. Numerical results are given, and are anticipated to be the values initially quoted on certificates and in reports of recertification. However, these values are subject to change upon future adjustment of estimated uncertainty components for the filters or changes in the observed bias with future determinations.
Technical Note (NIST TN) - 1715
Report Number


Absorbance, bias, certification, spectrophotometer, traceability, transmittance, transmittance density, uncertainty


Travis, J. , Smith, M. , Choquette, S. and Liu, H. (2011), Certified Transmittance Density Uncertainties for Standard Reference Materials using a Transfer Spectrophotometer, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed May 21, 2024)


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Created November 28, 2011, Updated June 2, 2021