Project period
Start: June 2021
End: May 2024
Project description
The overall objective of the project is to enable traceable areal roughness and dimensional measurements using optical 3D microscopy (focus-variation, confocal microscopy, coherence scanning interferometry) and optical distance sensors (confocal, interferometric), with special focus on giving guidance for selection of the most suitable instrumentation or settings for a particular measurement task.
To cover all aspects of this cross-scale project, the PTB departments 5.1 “Surface Metrology” and 5.3 “Coordinate Metrology” are collaborating in the TracOptic project.
Department 5.3 concentrates its activities on the measurement of the object geometry using three different measurement principles: focus-variation, confocal microscopy, and chromatic confocal distance sensing. Those instruments will be extensively characterised. Particular attention will be paid to a chromatic confocal point sensor. The aim is to implement a digital twin of this sensor and use it for estimating task-specific measurement uncertainties. Furthermore, the most significant influences caused by the measurement object will be examined in order to subsequently design suitable standardised tests.
Key research aspects:
- Selection and development of suitable material standards to characterise instruments, to systematically investigate effects caused by the measurement object, and to validate research results by performing industrial case studies
- Extensive comparison measurements investigating following aspects:
- Impact of the specimen’s slope and curvature
- Power spectral density of measurement data
- Measurement noise
- Impact of surface reflexion characteristics (bidirectional reflectance distribution function BRDF)
- Structural resolution
- Length measurement error
- Modelling of a chromatic confocal point sensor using Ray-Tracing
- Development of good practice guides for the selection of appropriate instrumentation and instrument settings for a given measurement task including a simplified uncertainty estimation
- Development of suitable standardized sensor test concepts
Further information can be found at the Euramet webpage or at the project webpage.
Projectpartners
Besides PTB (Germany) following national metrology institutes are part of the project: CEM (Spain), DFM (Denmark), GUM (Poland), INRIM (Italy), LNE (France), VTT (Finland), RISE (Sweden), VSL (The Netherlands).
Furthermore, the following institutes and companies are part of the project: Alicona Imaging GmbH (Austria), Centro Ricerche Fiat S.C.p.A. (Italy), Friedrich-Alexander-Universität Erlangen – Nürnberg (Germany), Fundacion Tekniker (Spain), Gesellschaft für Bild- und Signalverarbeitung (GBS) mbH (Germany), Ostschweizer Fachhochschule OST (Switzerland), Technische Universität Chemnitz (Germany), Technische Universität Clausthal (Germany), Technische Universität Kaiserslautern (Germany), The University of Nottingham (United Kingdom), twip optical solutions GmbH (Germany), Universität Kassel (Germany), Universität Leipzig (Germany), Universität Stuttgart (Germany), Zygo Corporation (USA).
Projectfunding
The three-year project is funded by the European Union within the framework of the “European Metrology Programme for Innovation and Research” (EMPIR) and coordinated by PTB department 5.1 “Surface Metrology” (Dr. Uwe Brand).