Fuel sensor calibration

[ggerhardt]

I calibrated my fuel sensors using the Skyview calibration routine. I must say, it could be better. First off, it asks you what the max capacity of your tank is. Well...hmmm...I don't know, that's why I'm calibrating them. So I put in a number that I figure should be about right (it wasn't). Then, you need to fill it in exactly 5gal increments. That's ok, but why not put in a box that says, oops, that was actually 5.2gal this time. Once you start the process, there is no correcting it. Kinda tough to ask the fuel truck to take the fuel back and lets try that again!

I kept track of the volumes entered and voltages on paper, tho, so I'm assuming I can dig into the calibration file and adjust the values. I'd recommend a calibration routine that offered a little more flexibility, tho.

Geoff
Velocity 173RG

 

[mmarien]

I agree the calibration is tedious at best but you only need to do it twice. Once for practice and once again for good measure. :

Just guessing here but I think the initial max capacity is to determine the increment for the calibration and the maximum amount on the gauge. Both of which can be adjusted later. The exact amounts are probably mute as I have more fuel climbing than descending. All depends on how the fuel sloshes around in your tank. If you think your car has a better fuel gauge try doing a wing over in your Focus and let us know how the fuel gauge handled that. But I digress. Some tricks if you want to fine tune your fuel gauge.

The calibration can be hand edited. Export the settings file to your thumb drive and open the *.dlg file with a text editor. Search for the calibration section of the file (ie: user_cal=). There should be a calibration section for each fuel tank and flaps and trim if you calibrated them. The calibration is simple with each calibration amount defined as:

            point={
                  volts=0.109649
                  value=5
                  }

If you know you put in 5.2 just adjust the amount. When you're done load the file back into Skyview.

The maximum amount can also be adjusted but you can do that in Skyview on the EMS SENSOR SETUP menu - page 7-52 of the Installation Menu. The calibration wizard doesn't stop when you reach the maximum amount. So if you want to calibrate your fuel in one gallon increments, just say the maximum capacity is ten gallons. I think it divides by ten and rounds to the nearest integer amount. It will probably calibrate in one gallon increments. You can adjust your gauge later to reflect the true max amount otherwise it will say 10+ for anything over 10 gallons.

Finally, if you go back to the fuel calibration wizard it will show you the voltage of the current amount in your tank. I'm not positive, but I think you can also do some editing there without recalibrating the entire tank again.

While there are several ways to fine tune the fuel amounts, what we really need is a fuel gauge arc where the empty part is black - like the fuel bar.

 

[ggerhardt]

Hey, thanks for the help. I have a feeling I'll do another calibration now that I know how it works. I'll just have to burn some fuel off. I have two tanks, so to calibrate, I pump all the fuel into one tank, then I have a 5gal tank that I incrementally fill the other tank with, then back to the other one. Its a rather long process, tho.

I lived in Saskatoon for 20yrs (1980-2000) - I grew up on a farm in South Eastern Saskatchewan (Kipling). I'm in Massachusetts now. I was home a year or so back and went flying with a friend there - pretty different flying on the prairies than out here! Not so many safe places to land in an emergency here...I'd much rather do my first test flight (likely next week) back home...

Geoff

 

[mmarien]

Hi Geoff

I just returned from Nova Scotia. The bush and rock is definitely different then the wide open prairies. We're kind of spoiled here with an estimated million miles of graded road for emergency landing. The rest is sort of flat also. Kind of a gift to pilots.

Good luck with the first flight.

 

[dynonsupport]

So if you go back into the calibration screen after doing the pours, you'll notice that you can edit the fuel calibration manually. You can also export the settings file and do it that way, but it IS possible to do it right there on SkyView.

Also, note that that initial question about how big the tank is just to divide the pours up reasonably. Ie, if you say 10, you get 2 gallon increments I think. If you say 50, it's 5 or 7 gallons increments. The system doesn't use it for the actual full point though.

 

[ggerhardt]

I didn't realize the calibration screen changed after its been calibrated, I'll have a look at it and see if I can clean it up there. Thanks.

Geoff