1. How do you prepare an interlaboratory study?

Given the potential economic consequences of EIL, the entire approach to be followed was the subject of an early standard, to ensure that the results obtained are recognized and accepted. This is described in parts 1 to 3 and 5 to 6 of the NF ISO 5725 series of standards.

Carrying out an EIL is rarely an individual initiative, but rather the result of a working group, which can be explained by its sometimes high cost and the significant resources required. The principle of the approach is to select a group of laboratories to carry out repeated measurements on one or more homogeneous samples, applying as closely as possible the method whose fidelity is to be assessed.

In practice, once a working group has identified the need to carry out an EIL, it appoints an Interlaboratory Study Organizer (ISO). The initial tasks of the OEIL are to:...