Development of primary reference facilities and measurement comparison of standard artifacts for the bidirectional transmittance distribution function

Loading...
Thumbnail Image
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2023-08-01
Major/Subject
Mcode
Degree programme
Language
en
Pages
9
Series
Review of Scientific Instruments, Volume 94, issue 8
Abstract
To determine the bidirectional transmittance distribution function (BTDF) of diffusely transmitting materials, two new primary facilities have been developed at the Physikalisch-Technische Bundesanstalt (PTB) and Aalto University (Aalto). A detailed description of both facilities and the different approaches used are presented in this paper. The performance of both facilities is compared by determining the BTDF of two different diffuser types in both in-plane and out-of-plane bidirectional geometries at four different wavelengths in the visible spectral range. Due to delayed completion of PTB’s primary facility, the measured BTDF values are compared between Aalto’s primary facility and another PTB setup, whose measurement scales are successfully transferred to PTB’s primary facility by an internal comparison. A thorough analysis of the measurement uncertainty is presented, leading to a combined k = 1 standard uncertainty of 0.8%-1.2% for PTB’s primary facility and 1.3%-1.7% for Aalto’s primary facility. The BTDF results obtained agree well within their expanded k = 2 uncertainty. This indirect bilateral comparison shows that Aalto’s and PTB’s new facilities are suited as primary reference setups for the determination of the BTDF. These studies also reveal action points to improved measurement capabilities and for a reduction of the measurement uncertainty, depending on the type of diffuser under test.
Description
Funding Information: The BxDiff project (Grant No. JRP 18SIB03) has received funding from the EMPIR program co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation program. J.F. gratefully acknowledges the support of the Braunschweig International Graduate School of Metrology B-IGSM. Publisher Copyright: © 2023 Author(s).
Keywords
Other note
Citation
Fu , J , Quast , T , Velke , E , Esslinger , M , Pastuschek , M , Schirmacher , A , Aschan , R , Manoocheri , F & Ikonen , E 2023 , ' Development of primary reference facilities and measurement comparison of standard artifacts for the bidirectional transmittance distribution function ' , Review of Scientific Instruments , vol. 94 , no. 8 , 083102 . https://doi.org/10.1063/5.0151803