What monitoring method should be used?
Monitoring vs. calibration

There are many different monitoring methods, and this fact sheet does not claim to cover them all. Rather, it proposes a sampling of them, enabling the laboratory to choose one (or more) that meets its expectations, and to initiate its implementation.

This implementation must be accompanied by an assessment of the risk of undetected drift in the measurement process. This risk assessment must determine the means to be used for monitoring (method and frequency).