Design Philosophy

The Optifuel system is inexpensive compared to the best systems available, but to get accurate results like the best systems you have to put effort in to the calibration process. We do not rely on perfect flow metering from the sensor like the other inexpensive systems do, where the only thing that you can adjust on these systems is the K value (amount of pulses per quantity of fuel). This type of data collection relies on a perfect linear output from the flow sensor. And then to compensate for inaccurate results additional inputs are added to the instrument like tank level senders. Relying on a fuel level sender is simply not accurate enough, if that was the case we would not bother with using a flow sensor. It would compromise the accuracy of the calibration as well as take responsibility away from the pilot to actually know how much fuel is in the tank before a flight.

When designing this system we believe that the instrument needs to be able to adjust sensor calibration for all scenarios. Doing a perfect installation and creating a laboratory like environment on your aircraft is costly and complicated. Expensive flow sensors are needed with a fuel pump pulse dampener added on the fuel line.

From the outset we have designed the instrument to have more
intelligence to be able to cope with non-linear flow sensor outputs, thereby allowing us to deliver an inexpensive yet very accurate instrument (well within 3% error) if a little effort has been put in to calibrate the instrument.

Refer to the flow sensor output chart. The output may seem linear, but what you are seeing is the rate of change of acceleration of the turbine which happens to be linear. But if you had to measure the total amount of pulses per quantity of fuel over different flow rates then the output would not be linear (which is what other systems hope for). On the Optifuel system, not only can you change the gradient (PARAM A - Rate of change of acceleration) of the output graph but you can also change where the graph intersects on the Flow Rate axis (PARAM B- accuracy over flow range).

Flow sensor output chart