Metre Convention was signed on May 20, 1875. The Convention establishes the International Bureau of Weights and Measures (BIPM) whose task is to provide a world measurements unity, to realize and maintain international standards, to compare national and international standards, to ensure coordination in the methods of measurement and to conduct and coordinate research on physical constants that are used in standards development. Principality of Serbia adhered to the Metre Convention on September 21, 1879. By accessing to the Metre Convention, the Principality of Serbia has undertaken to introduce the International System of Units (SI), to realize national standards in accordance with the definitions adopted by the General Conference on Weights and Measures (CGPM), as the governing body of the Convention, to periodically compares Serbian standards with international standards held by the International Bureau of Weights and Measures. Republic of Serbia continues its original membership of the Metre Convention from 1879. Mutual Recognition Arrangement for national measurement standards and for calibration and measurement certificates issued by national metrology institutes (CIPM MRA) was signed in October 1999. Federal Bureau of Measures and Precious Metals, as a national metrology institute of the Member State of the Metre Convention, signed on December 5, 2002, Mutual Recognition Arrangement for national measurement standards and for calibration and measurement certificates issued by national metrology institutes (CIPM MRA).