The aim of the JRP is to ensure the continuity of the mass unit between existing and new realisations by providing a means of accurately fixing the Planck constant with reference to the International Prototype Kilogram (IPK). The JRP has the objectives to:
- Develop and evaluate artefacts suitable for the determination of the Planck and Avogadro constants
- Provide appropriate procedures and apparatus for the mass transfer between in-vacuum experiments
- Evaluate the mass stability of suitably stored mass artefacts and develop the metrological infrastructure for the (medium term) maintenance of the mass unit and its dissemination based on different realisations
- Develop and adapt surface analysis techniques
- Develop and validate methods to allow the reproducible cleaning of primary mass standards
- Identify and evaluate the uncertainty components inherent in the mise-en-pratique and their propagation through the dissemination chain for the kilogram unit.
UME contributes to this project is given below;
WP1: Development and Evaluation of Artefacts Suitable to Provide Maintenance and Dissemination of a Redefined Kilogram
- The homogeneity and cleanliness of materials for use as mass transfer standards will be evaluated by analysis of the topography using AFM and Perthometer
- The homogeneity and roughness of the composite materials as reference mass standards
- The surface finish of the samples will be evaluated by AFM and perthometer
WP2: Development and Evaluation of Procedures and Techniques for The Mass Transfer Between Vacuum and Air
- The gravimetric comparison measurements of the mass standards made of different materials a pressure range between 10-6 hpa and 103 hpa will be made
- The selected methods for air - vacuum transfer of kilogram artefacts will be validated
WP3: Surface Effects and Dynamic Changes on The Artefact Surface Between Vacuum, Air and Selected Gases
- UME will jointly identify, assess and select appropriate analysis methods for static phase and dynamic phase
- Surface analysis in the static vacuum phase will be performed by XPS
WP4: Evaluation of The Mass Stability of Artefacts With a Focus on Storage, Cleaning and Transport Methods
- The efficiency and suitability of cleaning techniques will be investigated using BIPM, wet(Soxhlet) cleaning and ultrasonic cleaning methods
- UME will participated in intercomparison of primary mass standards
(Completed)