# calculate tank volume

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#### hussain

i need calculate the volum liquid inside horizontal cylinderical tank depending on liquid height

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#### Vedran Kosta

Dear Hussain,

Erect tank and than use formula: V=r*r*3,14*h ;-)

Harder way is solving triple integral, but I am afraid that was long ago when I was doing such things, so I cannot help you, sorry.

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#### dchartier

Hello;

If your PLC has trig functions, you could use the following link to calculate the volume based on the height of the liquid and the dimensions of the tank:
http://mathforum.org/library/drmath/view/54105.html

If not, then a look-up table should be easy to implement. Calculate the volume of the tank for a number of heights (based on the same formula as above) and build a one on one relation between the height and the calculated volume (in retentive memory) in the PLC.

Hope this helps,
Daniel Chartier

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#### Fred Loveless

It has been almost 30 years since I took geometry but I do believe the formula is:

v = ((pi)r^2)h

Where h is the height, and r is the radius.

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#### Vedran Kosta

I looked it up in my Bronstein/Semendjajew math book and I find this formula:

Area of circle (|>, (| part is S = 3,14*r*r/360*ALPHA, ALPHA = 2*arccos
(1-h/r)

So volume is:

V' = S*L, when level of liquid is h<r AND if h>=r:

V'' = L*(3,14*r*r-S), but in this case ALPHA = 2*arccos (1-(2r-h)/r)

L is length of cylindar, h is level of liquid, r is radius.

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