Based on the recommendations of the GULFMET at its third meeting held in Dubai on 19 March 2012, which included the mandate of the GULFMT Secretariat to redefine the functions and role of the technical committees (TCs) according to the latest developments, the GULFMET renamed the technical metrological committees to become compatible with international designations as follows: * Technical committee for mass measurements and related quantities * Technical Committee for electrical and magnetic measurements, time, and frequency, * Technical Committee for Thermometry and Dimensions, And based on the decision of the GSO Technical Council at its 34th meeting held in Riyadh on 24-25 December 2014, which includes the mandate of the GSO Secretariat to review technical work manuals and to contribute to support the participation of Member States in the meetings of the technical committees, this manual has been revised to be in line with the directions and aspirations of the Technical Council.