=EF=BBAs per my original reply, i added an equivalent pitot feeding the s
tatic port of the belite sensor on both aircraft. Easypeasy and works great.
Fuel rated sensor. Quite accurate. Satisfied with both.
Fwiw,
Cheers,
Pete :-)
> On Mar 9, 2021, at 12:09 PM, h&jeuropa <butcher43@att.net> wrote:
>
.net>
>
> Pete,
>
> The problem with the BeLite probe is that it is not a differential pressur
e transducer. The tank vent faces into the airstream and pressurizes the ta
nk. The amount of pressure varies with airspeed. While the amount of press
ure from the vent is small, the weight of fuel is also quite small. This wil
l affect the calibration.
>
> I have been using this method of measuring fuel level for many years. I s
tarted with the system Tony K from NZ published around 2000. Tony specified
a differential pressure transducer. Over the years I have upgraded with ne
wer transducers. After one of my upgrades I couldn't figure out why the cal
ibration in flight was different than that on the ground until I realized ab
out the vent pressure. Changing to a differential transducer solved the pro
blem. I am currently using MPXV4006DP transducers. Since they are not rate
d for fuel, I use a loop of tubing to force a column of air between the tran
sducer and the liquid.
>
> I agree with Will Daniell, having a tank sensor is not terribly useful. S
ince the Rotax only uses about 5 gph, you need accuracy of 1 gal to judge 12
minute endurance. That's difficult. The better solution is to use the "m
ain" tank and as it gets low, monitor fuel pressure. When fuel pressure sta
rts to drop, switch tanks. You can easily do this, especially with an EFIS,
and the engine won't miss a beat. Then you have the 3 gal in the reserve s
ide, roughly 30 minutes to land.
>
> As always, just my opinion and experience.
>
> Jim Butcher
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=500907#500907
>
>
>
>
>
>
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