The rulebook on opacimeters was published in the “Official Gazette of the RS”, number 23/2026 of March 12, 2026.

This rulebook specifies the requirements for opacimeters, labeling of opacimeters, the method of determining the fulfillment of requirements for opacimeters, the method of testing the type of opacimeters, measurement methods, as well as the method and conditions of certification of opacimeters. This rulebook enters into force on March 20, 2026, and on the day of its entry into force, the Rulebook on opacimeters ceases to be valid ("Official Gazette of the RS", number 15/15).