Let me tell some information about diesel
fuel consumption measurement.
(we are manufacturer of diesel
flow meters and use them in remote
fuel monitoring projects).
Yes, in most cases we need to measure both supply and return flow. And fuel curculation in supply/return lines usually much bigger than fuel consumption.
Expecially during idling. typical values during idling:
supply flow rate : 140 liters/hour
return flow rate : 138 liters/hour
fuel consumption : 2 liters/hour
Just imagine, how precise we have to measure 140 and 138 to receive value "2".
For example, meter error is 1%. It is not enough if you will install 2 fuel meters, each with 1% error. During idling you can have 200% error : 0 or 6 liters per hour instead of 2.
Same with temperature compensation. During idling you can't have good data when sensor does not use temperature compensation (return fuel is hotter, difference can be 20 degrees and more, 1.4 % of return volume).
Thats why we make Eurosens Delta flow meter
, each chamber has 0.3% precision and they are precalibrated. Also temperature compensation is built-in.
I think Maretron can do the same, but you need 2 Maretron for differential measurement. While Delta
flow meter already have 2 channels. IN fact, resulted price
is twice cheaper.
Version with NMEA2000 interface