C.16.MR:4.1 - Fix what the measurement is meant to determine

Specify the subject, Characteristic, Scale and conditions needed to distinguish the sought value. Include timing, location, population or averaging interval where they change the question. Use C.16:5.1-:5.2 for that specification.

Distinguish values that can differ across stages of the procedure. The open-circuit voltage before connecting a meter and the terminal voltage during measurement are different sought quantities. Either can be a legitimate target; choosing one determines the required relation.

Name the receiving question. Estimating a value, deciding whether it exceeds a limit and detecting a change can tolerate different remaining uncertainty. This choice helps decide which influences are consequential.