# Calculating volume of grain silo, was Level measurement in silo of corn by load cell

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#### Leon van Rensburg

I am testing formulas for calculating the volume in grain silos and I am interested in the techniques you use. The problem we have is that when grain enter the bottom cone (shaped from a circle to a rectangle) in a silo there is no geometry formula for it(that i know of).

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#### Dave Carton

You have to section off the silo into 2 sections geometrically to get a good approximation of the silo volume. The top section is of course a cylinder.

The next part seems a little tricky because you have a combination cone and pyramid shape, but it is not relevant if you simply determine the area of the openings going into and out of the cone. It doesn't really matter if the openings are circular or rectangular. The following formula assumes the cone's base and frustum are parallel to each other

Cone Volume =h/3*(A+a+SQRT(A*a))

where A= Area of the top (Frustum)of the cone
a= Area of the base of the cone
h= Height of the cone

Silo Volume =Cone Volume+Cylinder Volume.

Magic!

Dave Carton
ABB Automation Services

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#### Leon v Rensburg

We used that formula already and went even a step further to divide the bottom of the cone into 3 seperate area's. But the problem is when you put grain in the silo and when you take it out again. Because the grain is not level in the silo at all times.

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#### Kirk S. Hegwood

Charlie Griswold <[email protected]> wrote: >Johan, > >Conductive sensors have long suffered from corrosion eventually making >them ineffectual in liquids. [Kirk S. Hegwood] True. Even in our limited testing, corrosion was beginning to take place in some of the chemicals. >The most reliable method, if there is room in the jug, is a boyancy type >sensor. [Kirk S. Hegwood] Still playing with some ideas others have suggested.

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#### Melchor Hereu

I´m using well known formulas to determinate grain silos contain. I want to know what´s the usually error when you are calculating the mass of the grain in silos. Is the question understood? Thank for this information.

Is in USA any official instruction?