TS 1990

TS 1990 is a standard concerned with the general principles used in the field of quantities, units and symbols. It covers physical quantities, the notation used for quantity and unit symbols, and coherent unit symbols. In general technical use, documents of this kind support a common language for measurement, engineering and science, helping users present quantities consistently across calculations, drawings and technical records.

Why quantities, units and symbols need a common structure

In metrology, a quantity identifies a measurable property, while a unit provides the reference used to express its value numerically. Symbols make that expression compact and unambiguous across languages and disciplines. Coherent units are derived units built in a consistent way from base units, which helps preserve clarity in equations and derived calculations. This broader technical framework matters wherever numerical data must be compared, communicated or reproduced reliably.

What this standard covers at a practical level

• presentation and naming of physical quantities
• use of quantity and unit symbols
• coherent unit symbols
• general principles for terminology and notation
• a common approach for technical documentation and measurement writing

The scope points to a standard focused on shared principles rather than a detailed catalogue of conversion tables or application-specific rules. Its value lies in setting a consistent technical basis for expressing measurement information so that it can be read and compared more reliably across documents. TS 1990 is presented as equivalent to ISO 31-0:1992.