Demands refers to calibration method are one of the general criteria for practice that laboratories must accomplish in terms of implementation SRPS ISO/IEC 17025:2006 standards. Method for calibration is exact technical procedure for application process of calibration, in other words it’s exact technical procedure for determination characteristics of calibrated sample. Whether it’s about nonstandard methods, modified standard or methods developed by laboratories, before official use, these methods have to proof they’re well qualified in practice these methods refers to. The International Organisation for standardization ISO, published the standard methods for calibration of horizontal and vertical cylindrical tanks, and the subject of this presentation is method that modifies standard electro – optical method of measurement internal distances in favour of 3D laser scanners that are used for making capacity tables.