Four-year study of roughness patterns using weekly calibrations

In order to evaluate the stability and reproducibility of roughness measurements, calibrations of the same roughness standard were held over four years. Calibrations were performed in the Laboratório de Medição de Superfícies Ópticas (LMSO), on Mondays, between late January to early December every year. Here are presented and analyzed the calibration results and also the measurements of lab temperature and relative humid, at the time of calibration, in order to assess if there is any correlation between these influence factors in the obtained results. The LMSO lab is accredited by INMETRO (Brazilian NMI).