[AnthonyMouse]

Accuracy and safety margins are two different things.

Suppose you have to spec the capacity of a line regardless of what temperature it is, because you're not going to measure it in realtime at all. You estimate the highest temperature will be 105 degrees F, calculate the capacity at that temperature, add e.g. a 20% safety margin, and call that the capacity of the line.

That means when it's 40 degrees F, you could be operating with a 200% safety margin, which is unnecessarily conservative and wasteful. Conversely, because you're not measuring the temperature at all, your high temperature estimate could be wrong and there could be a day that it's 115 degrees F, your safety margin is completely gone and the line burns out. Whereas if you were monitoring the temperature, you'd lower the capacity of the line that day to still have a 20% safety margin and not have problems.