Most continuous fuel meas. system use a closed circular body with a paddle that
goes around and around as the fuel flows through it.  Each revolution is counted
 by a hall (magnetic) sensor, because a tiny magnet is inside each paddle, so th
e fuel system is completely closed.  I am familiar with this type of sensor beca
use of its use in small airplane engines.  It is extremely reliable.   You shoul
d be able to find a company that makes such a device on the WEB.  Perhaps if you
 find a picture, you can manufacture one of your own.
   Regards,
     Ron Fial.

At 08:35 AM 7/16/98 +0000, you wrote:
>Chuck Rice wrote:
>> You might try using a diaphragm to measure the fuel. Create a small chamber
>> with a inflow port and an outflow port. Divide the chamber in half with
>> the diaphragm. One side would contain gas and the two ports, the other
>> side would be sealed and contain air and a non-contact switch (If the
>> diaphragm breaks, would not want to spark a fire).
>
>I had thought of a chamber measurement, but never thought of the
>diaphragm. That would seem a real nice idea, but...
>
>> Close the output port and allow the fuel pump to fill the gas side of
>> the chamber expanding the diaphragm.
>
>...I can not close the output port. The fuel system is air tight. If I
>close the output port, I close the fuel to the engine and it stops. I
>would need some kind of parallel chambers: close one, use the other.
>Invert. Repeat.
>So, I would need four electro-valves, 2 diaphragms and 2 switches,
>besides the chambers. And all of this for one single device...
>
>>Close the input port and open the
>> output port. When enough fuel has been used to relax the diaphragm,
>> you count that as one unit. Then your fuel flow is the the number of
>> units times the volume of the diaphragm as related to time. The PIC
>> would use one output pin to control the inflow and outflow ports, and
>> one input pin connected to the switch on the diaphragm. -Chuck-
>
>Maybe I'm seeing it all wrong... What do you think?
>
>Nuno.
>
>__________________________________________________________________________
>> Chuck Rice                                     <mailto:Chuck@WildRice.com>
>
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