Lancair ListServ,
FWIW: In my Lancair IVP, I have VMS fuel capacitance
probes (AC output) which interface with Pricnceton
Electronics Interface units (AC in, DC out) which
communicates with my Chelton's EAU (originally made by
GRT).
I recently re-calibrated my fuel probes output
through the Princeton interface unit, as I wondered
about calibration drift after six+ years. Each tank
holds 55 gallons, and the step-reading system is based
on 10% increments.
As you can see, the output reading has changed over
time, resulting in a display error in fuel volume in the
tank. This explains the calculated Totalizer mismatch
(and WARNING message) with the probe's Fuel Quantity
reading, as occassionally seen on long flights. An
example is when there was actually 44 gallons in the
tank (ex, after using 11 gallons per fuel flow sensor),
the older fuel map told me there was 38.5 gallons...you
can understand the Totalizer error created by this.
I simply post this in case others find it relevant or
interesting.
Jeff L in New Jersey
LIVP