Flowmeters
Precision
We consider 0.5% precision on the flowmeter to be inadequate. The precision of the initial sensor is crucial, because in a system using multiple flowmeters, errors can combine and amplify in line with law of the propagation of errors.
With two classic oval wheel flowmeters precise to 0.5%, you will obtain consumption readings with an error rate of up to 30%, if the engine is idling. A measurement as imprecise as this renders consumption monitoring misleading. This is why we have selected flowmeters with measurements guaranteed precise to 0.1%.

Reliability

Flowmeters face rough treatment, so it is very important to choose carefully.
The pistons of the injection pump are responsible for fuel pulsations in the diesel supply line. These pulsations serve to vary the measurable flow at high frequency, and are responsible for a brief inversion. These same pulsations can also result in damage to the flowmeter. For these reasons, the flowmeter used must be capable of measuring the flow in both directions, and must also be extremely reactive. This is why we have selected flowmeters which measure the flow in both directions at a frequency of up to 5,000 impulsions per litre (as against less than 200 for some flowmeters on the market)he  pistons  of  the  injection pump  are  responsible  for fuel pulsations in the diesel supply line. These pulsations serve  to  vary  the measurable  flow  at  high  frequency, and  are  responsible  for  a  brief  inversion.  These  same pulsations can also result in damage to the flowmeter. For these reasons, the flowmeter used must know how to measure the flow in both directions, and be extremely reactive. This  is why we have selected  flowmeters measuring the flow in both directions at a frequency of up to 5,000 impulsions per litre (as against less than 200 for some flowmeters on the market)


  Precision levels* on differential measurements  
  Idling at full speed
Precision per flowmeter Final precision Final precision
0,1% 2 à 6 % 0,5 %
0,3 % 10 à 20 % < 1,8 %
1 % 20 à 60 % < 5 %
  * between the actual value and final value displayed  


TEMPERATUREOur  flowmeters  take  the  diesel  temperature  into account
In marine engines, diesel is consumed through the difference between the supply flow and the return. Yet the temperature of the fuel in the return circuit is 30°C higher than that of the supply circuit.

This difference in temperature modifies the volume of the fuel, rendering measurements inaccurate. The flowmeters used by Eco-Pilot monitor these differences in temperature, and take account of them. Consumption is calculated for a given reference temperature (for example, 15°C) – enabling you, for example, to compare it with the characteristics provided by your engine manufacturer.


KRAL FLOWMETERsWe have chosen to use helical screw flowmeters by KRAL - the only company producing flowmeters specifically designed for marine diesel engines.

VISIT KRAL WEBSITE FOR MORE INFORMATION