Measurement Uncertainty: New Definition, Viewpoints, and Laboratories

The Joint Committee for Guides in Metrology (JCGM) today presents a definition of measurement uncertainty that modifies the previous one and improves the management of scenarios other than scalar (quantitative) measurements, such as classificatory or qualitative (nominal and ordinal) properties. Nominal results are often found in biology and medicine. For the accreditation of medical laboratories and testing laboratories, both ISO 15189 and ISO 17025 require the management of these situations, using the professional expertise of specialists with the support of manufacturers. Some of the members of JCGM WG2 developed a discussion on the concept of measurement uncertainty and raised some criticisms. ISO produces detailed guides for this purpose, such as ISO 20914, ISO 27877, ISO 16393, ISO 20397-2, and ISO 22692. Laboratories now have all the tools they need to meet accreditation requirements on uncertainty.