Bob
That is a good suggestion. I considered that option as well but didn't
pursue it. I could not figure out a way to cleanly separate the
reflected scatter off the tank faces from overwhelming the detectors.
Perhaps a strip of foam barrier might work.
On Mon, Jun 23, 2014 at 7:34 AM, Robert Borger <rlborger@mac.com> wrote:
>
> Andrew,
>
> It is one fantastic idea!
>
> Question: Since you are looking at diffused/scattered light not transmitted
> light,
does it require 2 boards or could the whole thing be done with a single
board? LEDs down the left side & detectors down the right. Perhaps a light
barrier
between the emitters & detectors. Less wiring complication that way?
>
> Blue skies & tailwinds,
> Bob Borger
> Europa XS Tri, Rotax 914, Airmaster C/S Prop (50 hrs).
> Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
> 3705 Lynchburg Dr.
> Corinth, TX 76208-5331
> Cel: 817-992-1117
> rlborger@mac.com
>
>
> On Jun 22, 2014, at 9:12 PM, Andrew Sarangan <asarangan@gmail.com> wrote:
>
>
> Regarding the fuel indicator, I made a brief video to show how it
> works. Here is the link: https://www.youtube.com/watch?v=zagLfErDOQI
>
>
> On Wed, Jun 18, 2014 at 6:51 PM, Paul McAllister
> <paul.the.aviator@gmail.com> wrote:
>>
>> Andrew, since you are writing code you might like to incorporate compensation
tables for the shape of the tank so you get a linear scale.
>>
>> The system I have is a variant of Tony K's that weights the fuel with a 0 ~
1" pressure transducer. The fuel sloshing and tank shape compensation is done
with a PIC Micro. It has worked flawlessly for 10 years.
>>
>> Cheers, Paul
>>
>> -----Original Message-----
>> From: owner-europa-list-server@matronics.com
>> [mailto:owner-europa-list-server@matronics.com] On Behalf Of Andrew Sarangan
>> Sent: Tuesday, June 17, 2014 9:03 AM
>> To: Europa List
>> Subject: Re: Europa-List: Noncontact fuel level indicator
>>
>> I will take some photos and write up some details in a few days.
>>
>> The idea was based on what I accidentally observed one day when holding a
>> flash
light to the fuel tank. When the flash light is held below the fuel level,
the entire fluid lights up. When the flash light is above the level, the tank
lights up. The contrast across the fluid level is about 10x. This is due to
light
being trapped above or below the level. See attached pictures.
>>
>> So, I made a board with four LEDs in a column, and another board with
>> 10 photodetectors in a column. Using a microcontroller, I am flashing each
>> LED
in sequence, and then computing the liquid level based on the measured contrast.
The output is displayed on a 10-bar display. The LED board will attach to
the aft of the baggage bay bulkhead, with four holes to allow the light to get
through. The detector board has to attach somewhere on the front side of the
tank. This might be the tricky part because I need to make sure it is secure,
but also removable and does not interfere with the controls.
>
>
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