Report on the bilateral comparison between ZMDM (Serbia) and LNE-INM (France)(Euramet Project 766) EURAMET.PR-K6.1: Spectral regular transmittance

Abstract

The EURAMET-PR-K6.1 is a bilateral key comparison on spectral regular transmittance carried out in the framework of the Mutual Recognition Arrangement between the LNE-INM/CNAM (France) and the DMDM (Republic of Serbia). The LNE-INM/CNAM acted as the pilot laboratory and provided the link to the key comparison CCPR-K6.The aim of the comparison was restricted to checking the accuracy of the radiometric scale of spectrophotometers, using coloured glass filters with nominal transmittance of approximately 92%, 56%, 10%, 1% and 0.1%. The wavelengths of measurement were 380 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm and 1000 nm.The report describes in detail the facilities of the two participants for spectrophotometric measurements and the uncertainty budgets are presented. The comparison of the results of measurements carried out by the pilot laboratory before and after the circulation of the filters points out that the instability of the filters was not negligible. Moreover, for the coloured glass filters (filters B to D), the drift was wavelength-dependent. As a consequence, the drift of the filters during the comparison has been included in the calculation of the total uncertainty.Measurement results and their associated uncertainties were analysed in this report according to the Guidelines for CCPR Comparison Report Preparation but with some adjustment for taking into account that transmittance measurement have unit 1. Across the spectral region (380 nm to 1000 nm) there were eight wavelengths at which a comparison was made. These were treated entirely independently and thus the report describes eight comparisons for each type of filter.The linkage of this bilateral key comparison to the CCPR-K6 key comparison takes a particularly simple form because the pilot laboratory was also the pilot laboratory for the CCPR-K6 comparison, and the artefacts used were the same as those of CCPR-K6. The degrees of equivalence of DMDM have hence been evaluated by linking through values measured by the pilot laboratory.All the results and graphical representations of the unilateral degrees of equivalence with k = 2 are proposed in the final report.Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).