I may have missed this part of the discussion, but what happens if
auto and aviation fuel is mixed. As I recall there has been talk of either
auto or aviation fuel and the effect on the capacitance gauges. Unless
the tank is drained, once fuel type is mixed there will always be
a mixture of unknown ratio. It seems to me the calibration would be
changed every time fuel is added to the mixture. Any thoughts?
Ferg has a good idea of adding a capacitor for compensation, but because
of the mixture ratio problem a variable capacitor would have to be used and
you could calibrate your gauge just like tuning a radio....just kidding.
John Eckel, A230
----- Original Message -----
From: "Fergus Kyle" <VE3LVO@rac.ca>
Subject: Re: Europa-List: funny fuel gauge
>
> hey!
> That's the trouble with capacitance - it wants to know what
> it's
> looking at.......
> However, it IS capacitance. Therefore one could 'fudge' the reading by
> adding or applying a subsidiary capacitance (or if it's calculated to
> resistance at the gauge) to fool it. That would mean working out a circuit
> to insert for whichever parameter one wants - say, 100LL or Mogas. I'm not
> there yet, but will have to do something like that if I want accuracy.
> Failing that, one could apply a secondary scale to the gauge to
> read the secondary fuel type quantity. Whichever method means measuring,
> measuring and plotting.
> Good luck, I think,
> Ferg
> A064
> Oh, oh. I think PFA may want a word over there...................
>
> ----- Original Message -----
> From: "Rmi Guerner" <air.guerner@wanadoo.fr>
> To: <europa-list@matronics.com>
> Subject: Europa-List: funny fuel gauge
>
>
> <air.guerner@wanadoo.fr>
> |
> |
> | Hi all,
> | Surprisingly I get just the opposite with the Avelec capacitance fuel
> gauge: when full with mogas I consistently read 60 liters, and with Avgas
> 100LL I read 50 liters.
> | I also have another problem with this fuel gauging system: from time to
> time I have an "fuel tank fault" indication, or zero indication while the
> tank is full. Very difficult to troubleshoot as the problem is
> intermittent.
> Yesterday it happened only during a few minutes in the middle of a 3 hours
> flight. Any idea?
> | Remi Guerner
> | F-PGKL, XS 912S, s/n 395 monowheel, 320 hours
> |
> |
> | Subject: Re: Europa-List: Funny fuel gauge
> |
> <peter.rees05@ntlworld.com>
> |
> | Thats exactly the problem we had. Problem is that the gauge was
> calibrated
> | for Avgas - when we changed to Mogas, the gauge said that the tank was
> | always 3/4 full.
> |
> |
> |
> |
> |
> |
>
>
>
|