Overview
EN ISO 4064-2:2025 (adoption of ISO 4064-2:2024) defines the test methods for water meters used with cold potable water and hot water. Prepared by ISO/TC 30 in collaboration with CEN/TC 92, the document specifies the test programme, principles, equipment and procedures for type evaluation and initial verification of meter types (including ancillary devices where required by national rules). It supports issuance of OIML Certificates of Conformity when used together with ISO 4064‑1:2024 and ISO 4064‑3:2024 in accordance with the OIML system.
Key topics
- Scope of testing
- Type evaluation and initial verification for meters measuring cold and hot potable water.
- Testing of the complete meter and of separate subunits: measurement transducer (flow/volume sensor) and calculator/indicator.
- Application to ancillary devices as required by national regulations.
- Test programme and principles
- Definition of reference conditions, symbols, units and equations for metrological assessment.
- External examination procedures and preparation requirements.
- Requirements for repeatability, reproducibility, discrimination, sensitivity, durability and reliability.
- Environmental and EMC tests
- Climatic, mechanical and electromagnetic compatibility (EMC) considerations in accordance with referenced IEC standards (e.g., IEC 60068 series, IEC 61000 series).
- Tests for temperature ranges, humidity, vibration, shocks and electrical immunity/ immunity to disturbances.
- Metrological performance
- Procedures to assess allowable errors across flow ranges and temperature regimes, and tests for critical change values after disturbance or durability testing.
- Guidance on measurement uncertainty and conformity evaluation (referencing GUM and related guides).
- Documentation and reporting
Applications
- Ensures water meters meet legal and trade metrology requirements for accuracy, durability and EMC immunity.
- Used by:
- Manufacturers during product development and pre-market type approval.
- Notified bodies, test laboratories and conformity assessment bodies performing type evaluation and initial verification.
- Utilities and procurement teams specifying compliant meters for potable and hot-water distribution systems.
- Supports regulatory compliance (e.g., Directive 2014/32/EU / MI-001 requirements) and OIML certification pathways.
Related standards
- ISO 4064‑1:2024 - Metrological and technical requirements (essential companion).
- ISO 4064‑3:2024 - Test report format.
- IEC 60068 series (environmental testing) and IEC 61000 series (EMC), OIML D11 and OIML G13 for electronic instrument and laboratory planning guidance.
Keywords: EN ISO 4064-2:2025, water meter test methods, potable water meters, type evaluation, initial verification, metrological testing, EMC testing, OIML certification.