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Fuel Flow Calibration

mlwynn

Well Known Member
Hi all,

I have a GRT EIS 4000 and a red cube fuel flow meter. The version K instructions say to set the calibration at 200 and then adjust as you measure actual fuel consumption. The instructions with the red cube say to set it at 83 and adjust according to your fuel consumption. At 200, it is definitely reading way higher than the actual fuel flow. At 83, it seems to be substantially lower than I would expect it to be.

What calibration settings have others found?

Regards,

Michael Wynn
Phase 1
Livermore, CA
 
This is what phase 1 is all about. keep track of the fuel you add and the fuel the GRT says you have used and the manual will tell you how to make the adjustment. It will probably take a while to get the number accurate. If you are asking for a good starting point, I don't know what that would be for your setup.
 
I have to go to the hangar to see what my K factor number is.
I seem to recall I started with the red cube number; the manual is written for when GRT was supplying a different brand of flow sensor (Flow Scan 201, not the red cube).

As others have said, it takes a few iterations to zero it in.
 
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I performed fuel system flow test into a graduated container to ensure I had 125% of 27 gph(takeoff FF) and to "rough" calibrate the red cube. Mine flowed 42 gph. After flying, I have less than 1 gallon difference from fuel pump reading on every fill up. No adjustments were needed.
 
I installed the red cube and EIS with flocal set at 83. The readings were in the ballpark. After many months I tallied up the figures and made an 8% change to 90. Been there for most of 2014. The readings "feel" too high right now but I have not done the math to confirm or make a readjustment.

****EDIT **** Its about 2 weeks later than the above post and I just finished burning 200 gallons on a long holiday. In this case all the records were clear and clean. (unlike the records for the above adjustment). Well.....the data says to put it back very close to 83 (81 actually). :rolleyes:
 
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Sorry for the long delay.
My EIS FLO CAL setting is 83. It reads slightly on the conservative side (e.g., when it says I've used 40 gallons I've actually used about 38, so I have 2 more aboard than it says).

Bob
 
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