ISO (International Organization for Standardization) is the world's largest developer and publisher of International Standards.

website : www.iso.ch  

United Kingdom Accreditation Service (UKAS information site)

website : www.ukas.com

BSI British Standards is the National Standards Body of the UK, with a globally recognized reputation for independence, integrity and innovation in the production of standards that promote best practice.

website : www.bsi-global.com 

United Kingdom Accreditation Service(UKAS calibration and testing laboratory site)

website : www.ukas.org