ISO/IEC 80000

The international standard ISO 80000, or IEC 80000, is a style guide for the use of physical quantities and units of measurement, and formulas involving them, in scientific and educational documents worldwide. In most countries, the notations used in mathematics and science textbooks at schools and universities follow closely the guidelines in this standard.

The standard is jointly issued and maintained by the International Organization for Standardization (ISO) the International Electrotechnical Commission (IEC). The ISO/IEC 80000 family of standards was completed with the publication of Part 1 in November 2009.

Parts

The Standard has 14 parts:

part	name	former source	notes
ISO 80000-1	General	ISO 31-0, IEC 60027-1 and IEC 60027-3
ISO 80000-2	Mathematical signs and symbols to be used in the natural sciences and technology	ISO 31-11, IEC 60027-1
ISO 80000-3	Space and time	ISO 31-1 and ISO 31-2
ISO 80000-4	Mechanics	ISO 31-3
ISO 80000-5	Thermodynamics	ISO 31-4
IEC 80000-6	Electromagnetism	ISO 31-5, IEC 60027-1
ISO 80000-7	Light	ISO 31-6
ISO 80000-8	Acoustics	ISO 31-7
ISO 80000-9	Physical chemistry and molecular physics	ISO 31-8
ISO 80000-10	Atomic and nuclear physics	ISO 31-9 and ISO 31-10
ISO 80000-11	Characteristic numbers	ISO 31-12
ISO 80000-12	Solid state physics	ISO 31-13
IEC 80000-13	Information science and technology	subclauses 3.8 and 3.9 of IEC 60027-2:2005 and IEC 60027-3
IEC 80000-14	Telebiometrics related to human physiology	IEC 60027-7

International System of Quantities

The introduction to Part 1 states "The system of quantities, including the relations among the quantities used as the basis of the units of the SI, is named the International System of Quantities, denoted ISQ, in all languages."

Bridging language barriers

Anders J. Thor, the chairman of IEC TC 25, has said that there are four systems of writing that bridge all linguistic barriers regardless of the alphabet used. These systems are:

• the set of mathematical signs and symbols
• the SI
• the symbols for chemical elements
• the way of writing notes for music

The first three systems will be given in ISO/IEC 80000.

Binary prefixes

Main article: Binary prefix

A 1999 addendum to IEC 60027-2 on binary prefixes has resulted in some public interest in the standard and is still being widely discussed in the computer community, as it attempts to finally settle the confusion about whether, e.g., a kilobit corresponds to 1000 bits or 1024 bits.

The harmonized IEC 80000-13:2008 standard cancels and replaces subclauses 3.8 and 3.9 of IEC 60027-2:2005 (those defining Prefixes for binary multiples). The only significant change is the addition of explicit definitions for some quantities.

See also

• International Vocabulary of Metrology
• International System of Units
• BIPM — publishes freely available information on SI units
• NIST — official U.S. representative for SI; publishes freely available guide to use of SI

External links

• BIPM SI Brochure
• ISO TC12 standards — Quantities, units, symbols, conversion factors
• NIST Special Publication 330 — The International System of Units
• NIST Special Publication 811 — Guide for the Use of the International System of Units