[time-nuts] nubie querie

[Neville Michie]

As one who has measured vague things like hourglass time to great  
accuracy,
I would suggest finding a robust definition of "end of flow".
This would inevitably involve watching the flow past the "end of  
flow" to determine retrospectively
when the flow had effectively ceased.
To be fair to the hourglass you should at least use a caesium  
standard to keep time while
this process occurs, you can then confidently correct the reversals  
of the hourglass
for the turn-over dead time.
It should make for a simple timer,
cheers, Neville Michie