Water flow measuring sensors (preferred mode: Modbus)

[tailchopper]

Hi,

So i just want to install water flow measuring sensors in my kitchen and washroom to measure the volume of water usage every month or fortnightly. I have a datalogger which takes input as modbus so sensors should work directly on modbus or interface may be used between sensor and data loggers.

Please give me some info regarding water flow sensors available in the markets which suits my demand (they should send the data not just those which displays the real time flow)

Thanks