metrology Archives

Meter ruler showing SI units metric system, which can now go as high as quetta and ronna and low as ronto and quecto.

New Prefixes in the SI: ronto, quecto, ronna, quetta

ByMelanie Ross, Technical Products Developer December 6, 2022May 21, 2025

As of November 2022, in its first update to prefixes since 1991, the International System of Units (SI) now includes prefixes ronna, quetta, ronto, and…

Qualified empty calibration and testing laboratory that follows ANAB TR 2501 and ISO/IEC 17025 for accreditation.

ANAB | Laboratory

ANAB TR 2501 Requirements for Laboratory Accreditation

ByRyan Fischer, Senior Manager of Accreditation, Calibration June 8, 2022May 23, 2025

Technical requirements (TR) for specific programs are defined by ANAB to further outline additional requirements for the activities performed by laboratories within those programs. Technical…

Measuring mass is confusing on 2019 World Metrology Day from the change to the kilogram SI unit.

ANAB | Laboratory

Happy World Metrology Day: A Change to SI Units

ByRandy Long, Senior Manager of Accreditation May 20, 2019June 5, 2025

Effective on this World Metrology Day (May 20, 2019), the International System of Units is now based on a set of definitions each linked to…