I was trying to use this with pachube.
But also I am trying to simulate a normal digital water meter. Do you know how I can get from flow rate to actual metering (adding the cubic meters to the already registered ones) ?
Or to put it otherwise, how many pulses makes a liter (or a cubic metre)?
As you can see, I am not that good with maths! 
I know that 1Liter = 0.001 cubic meters, but that's all.