For using the 10cc per rev test dial on a water meter for the checking of
possibility of very small leaks, where the pointer barely moves.
So checking pointer arrow position, over an hour say, when are the times
most likely to have mains pressure increasing and when decreasing ? 06.30 to
07.30 falling 8.00 to 9.00 rising ? and static highest pressure in the
middle of the night, inconveniently.
What sort of corresponding times around 18.00 ?