Hello Graham,
I am following this thread for I shall also be looking at fitting a fuel
flow meter. Could I ask you to elaborate on your comment about ignoring the
return flow for you are only measuring the fuel to the engine. I think I
understand that with the placement of the Flowscan (from Marcel's the
schematic) no problem in measuring the fuel going to the engine. But with
the fuel coming back via the return line will that not eventually (after
going through the system) go back to the engine again via the Flowscan? The
question being, are the amounts so small not to worry about it and does this
just build in a safety margin? Sorry to sound thick on this, I am just
trying to get my head around what has been said so far and the schematic.
Robert
Robert Hatton
email: roberthatton1@googlemail.com
US Cell: +01 303 906 9395
UK Mobile: +44 79 66 184171
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Graham
Singleton
Sent: Wednesday, April 22, 2009 1:12 PM
Subject: Re: Europa-List: Fuel return line attachment point with 912UL
<grahamsingleton@btinternet.com>
The question is, how does ignoring the return flow affect the accuracy
>> of the fuel flow instrument? It depends on the quantity of the return
>> flow of course. Is there any data about this? Maybe in the rotax
>> maintenance manuals?
>>
>
> That's indeed the question I so far have not found an answer to. The
> only thing I was told by different people is that return flow varies
> with RPM, but no hard numbers on return flow have made it my way. So
> basically I *know* there will be an inaccuracy when ignoring return
> flow, but *do not know* just how large this inaccuracy is (hence my
> attempt to come up with something better for a single sender setup).
>
> Marcel
>
Marcel
The return flow does not affect your fuel flow to the engine and that is
what you are measuring. So you can forget about it with this configuration
Graham
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