Fuel-Level Sender

I installed the fuel-level sender a year ago. It's a nice unit from Centroid Products with no moving parts – it uses capacitance rather than a float. The one supplied in the kit was configured to integrate seamlessly with the Koso gauge. Specifically, it applies signal damping to prevent the reading from bouncing when the fuel sloshes in the tank and it maps the unique shape of the SL-Cs fuel tank to eight discrete restive/ohm-based values. The Koso then maps those eight values to the ten display bars on the gauge.

My MoTeC system can provide a more accurate and granular solution so I contacted Centroid to purchase a sender with an analogue 0-5V output an no tank shape compensation. They informed me that they would re-calibrate the sender at no cost, a nice surprise.

To calibrate the system, I will put some fuel in the tank and run the low pressure pump until it stops pumping being careful to not damage the pump by running dry for very long. I will take a voltage reading which will be the "empty" setting. I will then add a gallon of fuel and measure the voltage. I will repeat this until the voltage doesn't change at which point the tank is "full" as far as the sender is concerned. Of course, more fuel could be added at the very top of the tank and the fuel filler, but that's not a concern. Given that the tank holds 19.2 gallons, I will have 20 data points with all but one being approximately 5% apart. I could also go with half gallon increments, but I doubt that I'll have that much patience.

This data will then be entered into a custom map in MoTeC.