Report on supplementary comparison COOMET.PR-S3: refractive index

Abstract

The Supplementary Comparison COOMET.PR-S3 was carried out to ensure the correctness and comparability of refractive index of solid transparent materials in visible spectral range measured by the participants of the comparison within the uncertainties claimed for their measuring facility. COOMET.PR-S3 was conducted within the Regional Metrology Organization (RMO) "Euro-Asian Cooperation of National Metrological Institutions" known as COOMET, and has the RMO project number of 438/RU/08. The Comparison was piloted by the All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI). Five NMIs from three RMOs (COOMET, EURAMET and APMP) participated in the comparison. This report describes the measurement results of three prismatic samples made of different types of glass. Three participants, VNIIOFI, PTB and Ukrmetrteststandart have made measurements of the refractive index at the wavelengths of 480 nm, 509 nm, 546 nm, 589.3 nm, 644 nm, and three participants, VNIIOFI, INRiM and AIST at the wavelength of 632.8 nm. 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 (CIPM MRA).

Измерение Показателя Преломления С Помощью Гониометрической Системы

“…Для подтверждения возможности применения предложенного метода было проведено экспериментальное исследование трехгранной призмы, изготовленной компанией Schott AG (Германия) из стекла марки N-BK7. Данная призма была задействована в международных сличениях COOMET.PR-S3 [12] и значение её показателя преломления на различных длинах волн известно с очень высокой точностью.…”

Measurement of the refractive index using a goniometric system

“…To confirm the applicability of the proposed method, an experimental study of a triangular prism by Schott AG (Germany) from N-BK7 glass was carried out. This prism was used in international comparisons COOMET.PR-S3 [12] and the value of its refractive index at different wavelengths is known with very high accuracy.…”

Design of a Flow-Through Refractometer for Monitoring the State of Transparent Media with a Cylindrical Insert in the Form of a Vertical Section of a Pipeline

“…The principle of operation of a fl ow-through refractometer is based on the phenomenon of total internal refl ection (TIR) at the interface of two media [6,[15][16][17]. In recent decades, refractometers described in works [18][19][20] are used in the world to monitor the state of various media and to solve other problems. When studying stationary media, a high accuracy of measuring the refractive index with these devices was achieved (GOST 8.583-2011, "GSI.…”

“…When studying stationary media, a high accuracy of measuring the refractive index with these devices was achieved (GOST 8.583-2011, "GSI. State Verifi cation Scheme for Means of Measuring the Refractive Index") [19,[20][21][22]. However, the currently produced models of industrial fl ow-through refractometers with a change in the fl ow rate of the fl owing medium by more than two orders of magnitude with a simultaneous change in the temperature of the medium have a number of disadvantages.…”

“…The design of a fl ow-through refractometer and a method implementing the measurement of the refractive index. Taking into account the results of earlier studies of the state of fl owing media using fl ow-through refractometers [6,9,[15][16][17][18][19][20][21][22][23][24], a design of a fl ow-through refractometer with a vertical section of the pipeline has been developed. The block diagram of the refractometer is shown in Fig.…”