ISO 80000-5-2019 amd1-2025 PDF

Full title and description

ISO 80000-5:2019/Amd 1:2025 — Quantities and units — Part 5: Thermodynamics — Amendment 1. This amendment updates and supplements the second edition (2019) of ISO 80000-5 by adding, refining or correcting entries for thermodynamic quantities, symbols, definitions and units where required to align the part with current SI practice and editorial clarifications.

Abstract

This amendment provides one-page technical and editorial changes to ISO 80000-5:2019 (Part 5 of the ISO 80000 series) covering thermodynamics. It introduces clarified definitions, revised or additional symbols and unit entries, and any required conversion factors or notes to ensure consistency with the International System of Units and with recent updates across the ISO/IEC 80000 series. The amendment is intended as the authoritative update to be used together with ISO 80000-5:2019.

General information

• Status: Published
• Publication date: July 2025 (ISO catalogue entry: 2025‑07; some national catalogue listings record 23–24 July 2025)
• Publisher: International Organization for Standardization (ISO)
• ICS / categories: 01.060 – Quantities and units
• Edition / version: Edition 2 (2019) — Amendment 1 (2025)
• Number of pages: 1

Scope

Applies as an amendment to ISO 80000-5:2019. The document updates the Part 5 tables and textual entries that define thermodynamic quantities, their recommended symbols, short definitions and associated units (including conversion factors where relevant). It ensures compatibility with recent SI clarifications and with cross-references in other parts of the ISO 80000 series. The amendment is normative for users of ISO 80000-5:2019 and is intended to be used in conjunction with that part.

Key topics and requirements

• Clarified names and short definitions for selected thermodynamic quantities (e.g., specific energies, entropies, potentials where amended).
• Standardized quantity symbols and recommended typography for thermodynamics entries.
• Specification or correction of coherent units and conversion factors tied to SI practice.
• Editorial corrections and format updates to align tables and cross-references with other ISO 80000 parts.
• Harmonization notes reflecting recent SI clarifications and adoption across the ISO/IEC 80000 series.

Typical use and users

Used by metrologists, thermodynamics researchers, mechanical and chemical engineers, standards writers and technical editors, laboratories, publishers of scientific and engineering texts, software developers implementing units libraries, and national standards bodies. Typical use cases include ensuring consistent notation and units in technical documentation, test reports, educational materials, and computational libraries that represent thermodynamic quantities.

Related standards

Other parts of the ISO/IEC 80000 series and related documents commonly used alongside this amendment include ISO 80000-1 (General), ISO 80000-3 (Space and time), ISO 80000-4 (Mechanics), ISO 80000-12 (Condensed matter physics) and the IEC/ISO parts of the series (for example IEC 80000-13). The amendment is to be read together with ISO 80000-5:2019 (the base document).

Keywords

thermodynamics, quantities, units, symbols, SI, ISO 80000, amendment 2025, conversion factors, definitions

FAQ

Q: What is this standard?

A: It is Amendment 1 (2025) to ISO 80000-5:2019 — the part of the ISO 80000 series that defines quantities, symbols, definitions and units used in thermodynamics.

Q: What does it cover?

A: It covers technical and editorial updates to the thermodynamics tables and text in ISO 80000-5:2019, including clarified definitions, recommended symbols, units and any conversion factors or notes needed for consistency with the SI and the wider ISO/IEC 80000 family.

Q: Who typically uses it?

A: Metrologists, engineers, scientists, standards developers, technical authors, laboratory staff and software developers who need authoritative, standardized names, symbols and units for thermodynamic quantities.

Q: Is it current or superseded?

A: The amendment is published and current as of July 2025. It amends ISO 80000-5:2019 and is to be used together with that 2019 edition; it does not by itself replace the main part.

Q: Is it part of a series?

A: Yes — it is part of the ISO/IEC 80000 family (Quantities and units). Part 5 is the thermodynamics section; other related parts include ISO 80000-1 (General) and the other numbered parts in the series.

Q: What are the key keywords?

A: thermodynamics, quantities, units, symbols, SI, ISO 80000-5, amendment 2025.