Overview - EN ISO 772:2022 (Hydrometry: Vocabulary and symbols)
EN ISO 772:2022 is the sixth edition of the international vocabulary standard for hydrometry. Endorsed by CEN as EN ISO 772:2022, it defines standardized terms and symbols used across hydrometry and related standards. The document groups hydrometric terminology by topic (flow, open channels, instruments, sediment transport, precipitation, snow, groundwater, uncertainties) and includes Annex A listing symbols used in hydrometry. This edition supersedes ISO 772:2011 and adds new entries (notably precipitation and additional snow terms) and updated figures.
Keywords: ISO 772:2022, hydrometry vocabulary, hydrometric symbols, flow measurement, hydrology standards.
Key topics and technical content
- Core scope: Definitions of terms and symbols used in standards in the field of hydrometry.
- Structured clause coverage:
- Clause 3: General terms and definitions (hydrometry, flow, discharge, channel types, etc.)
- Clauses 4–7: Terms for velocity–area methods, flow measurement structures, dilution methods, instruments and equipment
- Clause 8: Sediment transport terminology
- Clauses 9–11: Precipitation, snow and groundwater terms (new/expanded in 2022)
- Clause 12: Uncertainties in hydrometric determinations
- Annex A: Symbols used in hydrometry; bibliography and index
- Standardization principles: Harmonizes terminology to avoid ambiguous or conflicting terms across countries and documents, following ISO editorial rules.
- Delivery: No normative references; the work was prepared by ISO/TC 113 (Hydrometry) with CEN/TC 318 collaboration.
Practical applications
- Ensures consistent terminology in technical reports, instruments specifications, sensor metadata, and regulatory documents.
- Facilitates interoperability of hydrometric data and comparison of measurements (discharge, runoff, sediment).
- Supports development and calibration of flow measurement systems, monitoring networks, and hydrological models.
- Useful for drafting and interpreting standards, contracts, environmental impact assessments, and research publications where precise hydrometric definitions are required.
Who should use this standard
- Hydrologists, hydrometric technicians and field engineers
- Water resources and environmental managers
- Instrument manufacturers and calibration laboratories
- Standards bodies, consultants, and researchers working with flow measurement, sediment transport, precipitation, snow and groundwater data
Related standards and references
- Produced by ISO/TC 113 (Hydrometry) in collaboration with CEN/TC 318
- Editorial alignment with ISO/IEC Directives and ISO 10241 series (terminology entry structure)
- Supersedes ISO 772:2011
Using EN ISO 772:2022 promotes clarity and reduces ambiguity in hydrometry practice, documentation and data exchange across national and international projects.
