ISO 80000-1:2009

Overview

ISO 80000-1:2009 - Quantities and units - Part 1: General - is the foundational part of the ISO/IEC “Quantities and units” series. Prepared by ISO/TC 12 in cooperation with IEC/TC 25 and published in 2009, it provides general information, definitions and principles for expressing physical and technical quantities, units, and symbols. The standard establishes the conceptual basis for the International System of Quantities (ISQ) and the International System of Units (SI) and serves as an introduction to the other parts of the ISO 80000 series. Note: ordinal quantities and nominal properties are outside its scope.

Key Topics

The standard covers essential technical topics and requirements, including:

• Terminology and definitions for quantity, kind of quantity, system of quantities, base and derived quantities, magnitude and measurement references (aligned with ISO/IEC Guide 99:2007).
• System of quantities (ISQ) and the conceptual link to the SI units, including the seven base quantities and base units (metre, kilogram, second, ampere, kelvin, mole, candela).
• Units and coherent unit systems: principles for defining derived units from base units and realizing unit values in practice.
• Quantity symbols and unit symbols: conventions for notation and typography (symbols in italics, distinction between quantities and units).
• Dimensions and dimensional analysis as they relate to quantity relationships.
• Printing and presentation rules for quantities, units and numerical values (Clause 7).
• Normative annexes on naming terms for physical quantities (Annex A), rounding of numbers (Annex B), and logarithmic quantities and their units (Annex C); plus an informative annex on international organizations (Annex D).

Applications

ISO 80000-1 is practical for organizations and professionals who need consistent, authoritative rules for expressing measurements:

• Metrologists and calibration laboratories implementing SI realizations and measurement traceability.
• Standards developers and technical committees harmonizing unit and symbol usage across sectors.
• Engineers, scientists and researchers preparing technical reports, data tables and publications.
• Instrument and software developers ensuring correct unit handling, data exchange and user interfaces.
• Technical editors, publishers and educators producing textbooks, standards documents and training materials.

Adopting ISO 80000-1 promotes clarity in measurement expressions, reduces ambiguity in engineering drawings, scientific papers and datasets, and enables reliable data interchange.

Related Standards

• ISO/IEC Guide 99:2007 (VIM - International vocabulary of metrology)
• SI Brochure (BIPM guidance on SI definitions and realizations)
• Other parts of the ISO 80000 series (Parts 2–14) and IEC parts (e.g., Part 6, Part 13) covering specific domains such as mechanics, electromagnetism and information science.

Keywords: ISO 80000-1, quantities and units, ISQ, SI units, unit symbols, measurement standards, quantities definitions, coherent unit systems.