Fuel level sender scales and offsets
Posted: Sun Mar 11, 2018 7:27 pm
Struggling with these calibrations. Craft is an RV9A.
I began by siphoning the fuel from the right tank, then removing the quick drain and draining the remaining fuel in the tank.
set the EIS to 100 and 10 scale and offset, per manual.
noted the reading on the EIS was 4.2
added fuel a gallon at a time.
EIS started to change on the 4th gallon...wrote it down.
continued to add fuel a gallon at a time.
EIS stopped changing after the 7th gallon..at 5.7..Hmmmmm
continued to fill up the tank.
Went thru the worksheet..came up with 533 scale factor and 440 offset..
Upon reviewing it all, I realized this is not going to be satisfactory for a 16 gallon tank!.. reading only from 3 to 7 or 8 gallons...
The craft had the standard Vans 2 1/4 round fuel gauges in it. they seemed to work ok in the 75 hours I flew it before I started the GRT upgrade..
IF I understand this GRT EIS fuel level calibration correctly, They recommend using the reading for full tanks as the level where the float sender stops changing..and the empty reading as the level it stops when going empty..in my case, it seems that I will have an empty reading at 3 gallons, and a full reading at 7. hmm..as I said, thats not going to work for a 16 gallon tank.OR at least, not very beneficial.
I went thru the math several times on the GRT worksheet.
Im scratching my head. If the sender output stopped increasing after the 7th gallon added...I guess it could be faulty..hard to believe it would only have a 3 to 7 gallon range of motion. (if its a float, which I think it is)
aircraft was level sitting in the hanger.
Any comments or Advice?
I began by siphoning the fuel from the right tank, then removing the quick drain and draining the remaining fuel in the tank.
set the EIS to 100 and 10 scale and offset, per manual.
noted the reading on the EIS was 4.2
added fuel a gallon at a time.
EIS started to change on the 4th gallon...wrote it down.
continued to add fuel a gallon at a time.
EIS stopped changing after the 7th gallon..at 5.7..Hmmmmm
continued to fill up the tank.
Went thru the worksheet..came up with 533 scale factor and 440 offset..
Upon reviewing it all, I realized this is not going to be satisfactory for a 16 gallon tank!.. reading only from 3 to 7 or 8 gallons...
The craft had the standard Vans 2 1/4 round fuel gauges in it. they seemed to work ok in the 75 hours I flew it before I started the GRT upgrade..
IF I understand this GRT EIS fuel level calibration correctly, They recommend using the reading for full tanks as the level where the float sender stops changing..and the empty reading as the level it stops when going empty..in my case, it seems that I will have an empty reading at 3 gallons, and a full reading at 7. hmm..as I said, thats not going to work for a 16 gallon tank.OR at least, not very beneficial.
I went thru the math several times on the GRT worksheet.
Im scratching my head. If the sender output stopped increasing after the 7th gallon added...I guess it could be faulty..hard to believe it would only have a 3 to 7 gallon range of motion. (if its a float, which I think it is)
aircraft was level sitting in the hanger.
Any comments or Advice?