A new optical method for high-accuracy determination of aperture area

E. Ikonen, P. Toivanen, A. Lassila

    Research output: Contribution to journalArticleScientificpeer-review

    34 Citations (Scopus)


    We have developed a direct optical method for aperture area measurement, based on constant, known irradiance over the aperture. The method is described and results of test measurements are given, including wavelength dependence of the effective aperture area. Systematic uncertainty components are studied experimentally to reach a relative uncertainty of 10 -4 for aperture sizes down to 3 mm in diameter. The most important advantages of the direct optical method are that it does not require any reference aperture, it can be applied to apertures of any shape, and the calibration setup is similar to the actual use of the apertures in filter radiometers.

    Original languageEnglish
    Pages (from-to)369-372
    Number of pages4
    Issue number4
    Publication statusPublished - 1 Dec 1998
    MoE publication typeA1 Journal article-refereed


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