valider par ajout connu

OBS: Renseignements fournis par un chimiste à Environnement Canada.

CONT: Accuracy in sampling analysis could be determined by analyzing a reference material of known concentration (or value), or by re-analyzing a sample to which a material of known concentration has been added (recovery method). For example, if T is the total concentration of a water quality parameter in a spiked sample, U is the concentration of the same parameter in the unspiked sample, and A is the amount of the parameter added to the hitherto unspiked sample, the percent recovery R is calculated as R = 100(T-U)/A.