With the development of industry and the emergence of a global market there is a need to ensure the product quality. An important part of this are the laboratories whose professional approach provides quality testing of products and production equipment. The aim of this thesis is to define procedures by which the Laboratory for engines and vehicles would become accredited for testing internal combustion engines used to power the non-road machinery. The paper made a brief review of Regulation No. 401 (issue 02) and Directive 97/68/EC. An insight is given into the accreditation process in Croatia and an overview of the Croatian Accreditation Agency. The influence of standards on the world market is analyzed and is given an overview of the most important world of preferred houses, as well as the Croatian Standards Institute. The norms of the utmost importance for the process of accreditation of the Laboratory for engines and vehicles are listed and analyzed, and the process of implementation of standards in the system of the laboratory in accordance with ISO / IEC 17025 is described. Next a detailed insight into metrology is given. The impact of metrology on industry is described and explained; the basic concepts are described as well as the most common methods of determining measurement uncertainty. At the end of the article the procedure for determining the uncertainty of measurement devices for torque and speed on the hydraulic brake SCHENCK type D 400 - 1e is shown. The results and compared with the required values from the standards. In the annex is written the general procedure of calibration devices for measuring torque and speed to the hydraulic brake SCHENCK type D 400 - 1e which will be implemented in the work of the laboratory.