Fuel Tank Calibration

I'll take try at this....off the top of my head

Volume = (1/2 pi r^{2 _•} h) + (1/4 (pi r^{2 _•} 2r tan Ø))

Ø = angle the cylinder is tipped

r= radius of your cylinder

h = lowest point of liquid - so measured from the highest elavation of the cylinder. So this is the path I'm assumed you'd place the dipstick.

We could maybe make things easier for you if you gave us more information!

Where is your inspection port? High end? Low end? Middle?

Please be as clear as possible when asking such questions.

Hallo

need to know how to calibrate a cyclindrical tank.l have the dimensions but need to the formulas and other parameters included.

Regards

Is your tank aligned as in "a" or "b" and where is the dipstick to be inserted?

I assumed orientation "b"

(Great illustrations BTW)

I reckon that in that orientation, 3.8º isn't really worth worrying about - given measuring errors, distortions in the tank etc., unless it has a pretty big radius-to-height ratio. (Also praise for the pics).

Dear Mr.masu,

For orientation "a" the liquid level segment to be calculated, using Trigonometry and multiply the area by length and you will get the Volume.

I will post the Formula, this evening or to-morrow.

For orientation "b" every one knows, as (3.14) x (r^2) x h.

DHAYANANDHAN.S

It is virtually impossible to do this using maths due to tank deformity, slope, fluid temperature, air pressure, specific gravity, etc. Tanks are never exact cylinders and usually have domed ends. Your dip stick/probe might not be perpendicular in the tank.

My suggestion is:

1. fit your measuring device, Dip stick, probe, etc.

2. add liquid of the same specific gravity in small measured amounts and mark the dip stick at each increment in level.

We do this sometimes for underground petrol tanks and it is relatively quick and accurate. If you are using a dip stick remember to fit a 'striker plate' to avoid wearing a hole in the tank bottom and subtract this plate thickness from the stick length.

Good luck

Hi

From the way the question is put, (see JohnDG post) here's an answer that might suits you best:

Step 1. fill your tanks to max capacity, drain to calibrated tank you now know the total.

Step 2. fix your dip-stick point, Refill the tank to max again, than start draining it again to the calibrated tank, marking the quantity drained on the dipstick, this will be your remaining usable fuel, less a sump quantity, if you have one, and you are done.

For very quick and rough estimations,

3.8 deg tilting will make a small difference so take it as horizontal and subtract some 7 to 8 % from the total assuming you can top it to avoid any air trapped within, and you be on the safe side

Wangito.

I have done some calculations on a horizontal tank with a 3.8º slope as in a in the drawing. When the level drops to the base of the upper end of the tank there is about 5% of the total tank volume left. What I suggest is that you use the profile for a standard cylindrical tank and then offset it by the 5% to account for the slope. If you need more details post your question here.

My gut tells me that orientation "a" is correct and that the offset from horizontal is intentional to facilitate complete drainage. If not, why don't you level it?

geowanu: looking over the other replies (including my own), I reckon Tom's come up with the best idea (which is in your title line); forget the maths - just Calibrate it!

Use stilljester's formula, weld a bung into the lowest point on the tank and elbow a pipe to vertical with either a cut out, glass tube and scale or just a solid wall tube with a calibrated dipstick to get the h dimension.

For those that are interested about the drawings they are done with a very expensive package called DeltaCAD. Follow the links for details.

http://www.deltacad.com/

Since I purchased a copy the price has gone up by 100%, it now cost about US$40 it's well documented has a good tutorial and is easy to use. It's a drafting package so you can't do fancy things like 3D modeling but it beats the hell out of a drawing board.