5. Our advice

5.1 Use proficiency test results to improve your measurements

Proficiency testing is thought to exist because :

• Accreditation has become an obligation for any laboratory wishing to sell its services or, more simply, belonging to a quality-assured company;

• required by Cofrac auditors;

As a result, analysts tend to regard them as a kind of "pensum" to be got rid of as cheaply as possible. This is a pity, because CILs are a remarkable way of understanding the critical points of a method... provided that you take part in the meetings at which the results are analysed. This seems to be increasingly rare, if test organizers are to be believed.