Intercomparison of flatness measurements of an optical flat at apertures of up to 150 mm in diameter

Susanne Quabis, Michael Schulz, Gerhard Ehret, Muharrem Asar, Peter Balling, Petr Kren, R.H. Bergmans, A. Küng, Antti Lassila, D. Putland, D. Williams, H. Pirée, E. Prieto, M. Pérez, L. Svedova, Z. Ramotowski, M. Vannoni, F. Hungwe, Y. Kang

Research output: Contribution to journalArticleScientificpeer-review

4 Citations (Scopus)


Recently, a scientific comparison of flatness measuring instruments at European National Metrology Institutes (NMIs) was performed in the framework of EURAMET. The specimen was a well-polished optical surface with a maximum measurement aperture of 150 mm in diameter. Here, we present an evaluation concept, which allows the determination of a mean flatness map taking into account different lateral resolutions of the instruments and different orientations of the specimen during measurement. We found that all measurements are in agreement with the mean flatness map within the uncertainty intervals stated by the participants. The aim of this scientific comparison is to specify an appropriate operation and evaluation procedure for future comparisons.
Original languageEnglish
Pages (from-to)85-93
Number of pages9
Issue number1
Publication statusPublished - 1 Feb 2017
MoE publication typeA1 Journal article-refereed


  • uncertainty analysis
  • comparison
  • deflectometry
  • flatness measurements
  • lateral resolution
  • measuring instruments
  • national metrology institutes
  • uncertainty intervals
  • interferometry

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