Mathematical equation for volume

[O2 Mash]

I am looking for a math equation to figure out the volume (gallons) of my collection of brew pots. I'd rather not fill up milk jugs with water and empty them into the pot to see how big they are. Does anyone know how to figure this out? I'm thinking if I know the diameter and height, it should be easily calculated.

[wild]

I believe it is
VOL= 3.1415*R^2*HT
Where R = Radius
R^2 = Radius squared
HT = Height

[studentofbeer]

pi*r^2*h =v

so 3.14159 (probably way too many sig figs) or whatever times the square of the radius of the base times the height equals the volume. (i assume we are talking cylinders here.) that would give you cubic inches, assuming you measure in inches.

then looking online i found that 231 cubic inches equals one gallon. so divide your volume by 231 and you should have gallons!

[O2 Mash]

Studentofbeer & Wild....... you are wise beyond your years. I knew there were many intelligent beer lovers on this board. Thanks for the help, this will be much more convenient than dumping gallon after gallon of water into my brewpot.......not that that's a bad thing, I just want to make sure I am able to BREW when I put water in it!!

[Caffinehog]

Do a little calculus, and you can calculate for the V-vessel or a conical. Fortunately, I'm not that nerdy.

[studentofbeer]

yeah i was kinda hoping he had a funky-shaped pot so i could brush off my calculus. been too long...

[wild]

Too late, I think my sliderule battery just died. :D

W

[bigmf]

Originally posted by Caffinehog
Do a little calculus, and you can calculate for the V-vessel or a conical. Fortunately, I'm not that nerdy.

That sounds like a challenge. OK I'll be that nerdy... the volume of a cone is V= 1/3 times pi times the radius squared times height. (V=(pi*r^2*h)/3) Do I get some kind of nerd prize now?

M.

[Caffinehog]

Well, first, you need to account for the fact that the radius of the base of the cone increases as you fill it. Then you need to account for the hemispherical top!

[BigRed]

Originally posted by Caffinehog
Well, first, you need to account for the fact that the radius of the base of the cone increases as you fill it. Then you need to account for the hemispherical top!

Nope - he is only looking for the vol. of his entire pot. If he is trying to figure out how much he actually has in there, then yes.

[O2 Mash]

Yup, they are just cylindrical brewpots. I tested the formula, and bingo. It seems just about right. Thanks again.

[O2 Mash]

Okay you mathematicians, seeing as you did so well on the first one...... got another one for you.

I know the radius and depth of my brewpot to figure out total volume in gallons (thanks Studentofbeer & Wild).

Now, I need to mark gradiations on my pot; how would I figure out where to mark the pot per every gallon of water? In other words, I add a gallon of water, how much higher does the water rise. tick, tock, tick, tock..... I hear the theme song from Jeopardy in the background.

[wild]

This goes back to the number of gallons you've now calculated for your pot is in ratio to how many inches tall your pot is. For example; if your pot is 4 gallons and is 16 inches tall, then each gallon will take 4 inches of the pot to fill.

W

[O2 Mash]

Originally posted by wild
This goes back to the number of gallons you've now calculated for your pot is in ratio to how many inches tall your pot is. For example; if your pot is 4 gallons and is 16 inches tall, then each gallon will take 4 inches of the pot to fill.

W

:o DUH, I should have been able to figure that one out, kind of embarrassing. I guess that's why I'm in sales.

[sbrisk]

http://www.equationsheet.com/search.php?SID=JSXGWDPZ&searchstring=volume&searchfield=Equation+Description

[Bruno_78]

Ok, I've got another one. On my converted keg boiling pot, I need to make some graduated marks. How do I take into consideration the curved bottom of the keg?

[fretlessman71]

Since there's no way to see your pot, it's going to be pretty hard to come up with a formula for that. I'd start pouring pints in one at a time and make your marks from there. Once you get to the vertical part of the side, you can use gallons instead and make the rest of your marks afterwards if you want.

There comes a point in time where we use our heads a bit too much... I mean, after all, this is BEER we're talking about. Remember the sage advice of our good friend Charlie.... :)

[YamahaXS]

Well, one advantage to filling them stepwise with a know volume would be that you could mark off intervals as you go.