Confidence is important because …
- Everybody needs to have confidence that they are sharing a common understanding of what is meant by expressions of measurement such as metre, kilogram, litre, watt, second, candela, etc.
- Confidence in measurement is vital in enabling metrology to link human activities across different countries and professions.
- This confidence becomes enhanced with the increased use of common units of measurement, common measuring procedures and network co-operation.
- This confidence is further enhanced by the recognition and mutual testing of measurement standards as well as the recognition of the technical competence, through accreditation, of metrology laboratories in different countries.
When is a measurement result valid?
A measurement result is valid when it is related, through an unbroken chain of comparisons, all having stated uncertainties, to references at the higher levels, ending at the primary standard.
In other words, a measurement is valid when:
- It is done to an accuracy that makes sense and can lead to proper decision making;
- The measuring equipment used needs to be calibrated to standards which are traceable to primary standards.
- The accuracy of the measuring equipment has to be within the limits of errors allowed, or any error found is duly compensated for.
