Get your HBT Growlers, Shirts and Membership before the Rush!

 Home Brew Forums > Making a Volume Measuring Stick
11-12-2011, 03:48 AM   #1
Rcole
Feedback Score: 0 reviews
Recipes

Join Date: Jan 2011
Location: Providence, Rhode Island
Posts: 88
Liked 9 Times on 7 Posts
Likes Given: 2

 Making a Volume Measuring Stick

Hi,

I'm sure this formula is on the boards here somewhere, but thought I would post the formula for marking a stick to measure the volume of liquid in a round container as a function of the height of the liquid. So, here is how to figure out where to mark your dowel to indicate number of gallons:

Formula to Calculate Height Based on Volume is

h = v/pi r^2

Where h is height, v is volume, pi is 3.1415, and r^2 is radius squared

Note: 1 gallon = 231 cu inches

------------------

Here is an example of how to solve for height in inches of a given volume, in a given pot diameter, say

4 gal. in 14" pot

h = v / (pi)(r^2)

h = 4*231/(3.1415)(7^2)

h = 924/(3.1415)(49)

h = 924/153.93

h = 6" for 4 gallons in 14" pot

__________________

2
People Like This
11-12-2011, 04:35 AM   #2
Dilligans
Feedback Score: 0 reviews
Recipes

Join Date: Jun 2011
Location: Acworth, Ga
Posts: 89
Liked 5 Times on 3 Posts
Likes Given: 2

all I did was pour a gallon of water in a pot then mark it... then poured two gallons then marked it ... 3. 4.. etc... I dont know about using a formula... but then again I forgot everything in learned in high school and college.

__________________

3
People Like This
11-12-2011, 04:41 AM   #3
franklinswheat
Feedback Score: 0 reviews
Recipes

Join Date: Jun 2010
Location: new york
Posts: 151

At first I thought this thread was funny because I thought it was somebody's sarcastic response then I realized it was 100% serious. That formula makes baby Jesus cry.

__________________

Hi

11-12-2011, 04:58 AM   #4
day_trippr
Feedback Score: 0 reviews
Recipes

Join Date: May 2011
Location: Stow, MA
Posts: 11,223
Liked 1384 Times on 1116 Posts

It better be one hell of a fancy stick...

Cheers

__________________

11-12-2011, 11:31 AM   #5
SwampassJ
Feedback Score: 0 reviews
Recipes

Join Date: Mar 2010
Location: Coral Springs, FL
Posts: 2,162
Liked 37 Times on 34 Posts
Likes Given: 53

Take the largest accurate measuring cup you have and measure out a gallon in a pitcher or something. Mark the pitcher and then began filling the kettle from the pitcher. Ever addition mark or knotch a spoon or a spare plastic racking tube. The people at the brew store thought it was the neatest thing when I broke out the measuring stick.

__________________

BLAH BLAH BLAH

11-12-2011, 11:38 AM   #6
Pappers_
Moderator
Feedback Score: 0 reviews

Recipes

Join Date: Jan 2009
Location: Chicago
Posts: 12,105
Liked 1028 Times on 720 Posts
Likes Given: 2105

Quote:
 Originally Posted by Dilligans all I did was pour a gallon of water in a pot then mark it... then poured two gallons then marked it ... 3. 4.. etc... I dont know about using a formula... but then again I forgot everything in learned in high school and college.
This is what I did, too
__________________
http://www.singingboysbrewing.com

My wife's book "Uncovering Lives: Discovering One Immigrant Generation's Secrets and Lives of Forgiveness, Grace and Healing"

"People who ask a question want a conversation as much as they want an answer." b-boy

11-12-2011, 12:32 PM   #7
tmurph6
Feedback Score: 0 reviews
Recipes

Join Date: Dec 2010
Location: katy, tx
Posts: 398
Liked 26 Times on 13 Posts
Likes Given: 1

Pouring in water is more accurate than measuring and calculating. With every measurement you introduce error. Also pots aren't always perfect cylinders. The error may be minimal, but when you can get it just about perfect with the volume method, why not? There's a time and place for calculation.

Example, you want to figure out the optimal place to put a floor drain. Do you shoot elevations and measure grade to find out where the low point is? No, you spray water on the ground and see where it collects. Easiest answer is usually the best.

__________________

11-12-2011, 12:44 PM   #8
MichaelBrock
Feedback Score: 0 reviews

Recipes

Join Date: Jun 2011
Location: Alachua, FL
Posts: 488
Liked 31 Times on 26 Posts
Likes Given: 38

When I first started brewing I set out to take the scientific approach to measuring my volume. The plan was to measure the height of the water with a nice stainless steel ruler and calculate the volume. Unfortunately, my pot has a bowed bottom and that wasn't going to work. So I fell back to pouring water in the pot in set volumes and marking a piece of pvc. The math is pretty but not always practical (and this from a physics degree carrying computer programmer).

__________________

11-12-2011, 12:45 PM   #9
emjay
Feedback Score: 1 reviews

Recipes

Join Date: Jan 2011
Location: Toronto, Ontario
Posts: 12,701
Liked 1714 Times on 1602 Posts
Likes Given: 1

GL using this formula in a Blichmann kettle...

Then again, it already has a calibrated sightglass, so I guess it doesn't matter.

__________________

11-12-2011, 01:17 PM   #10
chezhed
Feedback Score: 0 reviews
Recipes

Join Date: Dec 2010
Location: Mission, TX
Posts: 497
Liked 33 Times on 32 Posts
Likes Given: 29

There's a time for common sense/practicality and a time for science.
The smart individual knows when to use what, no matter which

__________________

Green Bay Packers - 13 Time World Champions
______________________________________
Jygomundi Brews
I'm on Untappd - chezhed