Measurement is not an end in itself …!
Working as a metrologist with other metrologists each and every day might lead one to think that measurement is in everyone’s minds. But of course most people are not interested in the measurement itself, but rather in using the result of a measurement to make some kind of decision.
Decisions based on the objective evidence provided by measurement could be for instance:
• control of manufacturing processes
• verifying and certifying products against specifications
• guaranteeing safety, security and protect the environment
The assurance of quality of a wide range of products and services, which has been a primary focus internationally since several decades back and as embodied in the requirements of international standards/norms on management systems such as ISO 9000, has rather re-inforced the importance of measurement in recent years.
While measurement obviously has an important role to play in general quality assurance – such as in say the inspection and control of production – it will be useful in our discussion of measurement uncertainty to examine a specific kind of quality assurance – namely of the measurements themselves. As will be seen, measurement error, including estimates uncertainty and limits on accuracy, is a quantitative estimate of the quality of our measurements, and has to be accounted for when making decisions.