This document is applicable to the type evaluation and initial verification testing of water meters for cold potable water and hot water as defined in ISO 4064-1:2024|OIML R 49‑1:2024. OIML Certificates of conformity can be issued for water meters under the scope of the OIML Certificate System, provided that this document, ISO 4064-1:2024|OIML R 49‑1:2024 and ISO 4064-3:2024|OIML R 49‑3:2024 are used in accordance with the rules of the system.

This document sets out details of the test programme, principles, equipment and procedures to be used for the type evaluation, and initial verification of a meter type.

The provisions of this document also apply to ancillary devices, if required by national regulations.

The provisions include requirements for testing the complete water meter and for testing the measurement transducer (including the flow or volume sensor) and the calculator (including the indicating device) of a water meter as separate units.