Chemical metrology.

The phrase chemical metrology generates a wide variety of responses from analytical chemists and a degree of confusion. This technical brief aims to dispel the mythology of metrology, explain important aspects and demonstrate the value of metrology to chemical measurements. It is shown that the basic principles of metrology have been applied since ancient times and served well for thousands of years as the key to consistent measurements. Application of the principles to physical measurements was formalised towards the end of the 19th century to meets the needs of industrialisation and global trade. The most recent change in global adoption of metrology took place at the end of the 20th century with the decision to extend the system to analytical chemistry. The brief describes how this decision is being implemented and the progress which has been made towards an international infrastructure for chemical and more recently biological measurements.