Within Days of open doors on the occasion of marking the 20th May - the World Metrology Day pupils of third year, department jeweler of polytechnics school “Polytechnics-school for new technologies” from Zemun visited Directorate of Measures and Precious Metals. After they were introduced with history, place, role and importance of Directorate, study visit was continued with a tour through Laboratory for precious metals articles control. During the visit, pupils had a chance to get familiarized with method of hallmarking and determination of fineness degree of precious metals articles.