Well think about it, with an analogy. If you don't look at an odometer in a car during a particular drive, is it being used? Sure, it's doing it's job, silently clocking off the miles, at some point it might be checked such as during an inspection, or for oil change purposes, or at resale. Even if it's not looked at. Same could be said for oil pressure gauges, or temperature gauges in various vehicles. Do you know some days I don't even check the time on my watch! But it's right there on my wrist, just in case I need to check it.