Analysis of multiscale measurements of porous microstructures based on 3D optical microscopes

In this article, a multiscale measurement strategy is introduced to analyze porous microstructures and the main influences on the measurement accuracy of 3D optical microscopes are investigated. The purpose is to explore the fundamental relationship between resolution, magnification and imaging in optical systems derived from using different optical lenses and their impacts on the characterization of porous microstructures. A confocal laser scanning microscope with different lenses is used for the data acquisition. Afterwards, a post-processing for data combined with image processing is carried out to analyze the geometry differences of identical pores. The results show that the numerical aperture is the primary factor causing measurement differences of the same micro object rather than the magnification of a lens and the calibrated image pixel resolution. Moreover, the assessed geometry differences strongly depend on the size or the scale of the microstructures. This phenomenon can be treated as a good verification example for the classic Abbe-theory.