# Find the volume of liquid when the tank isn't level

• Dec 8th 2012, 12:29 PM
Ken661
Find the volume of liquid when the tank isn't level
Hello, I don't know if I am in the right forum but, my question is this. I am using a float to measure the amount of oil in a tank. The thank is in the shape of an obround. It holds around 275 gallon and the dimensions are approximations width a depth of 48", height = 70", Length 60". It works fine. I need to find out the amount of oil if the tank isn't level on the x or y or both x and y axis. The sensor can be located anywhere along the apex of the tank. The float is a ball tether to take up reel attached to this take up reel which in turn is attached to gear. A hall effect sensor sends a pulse to a microprocessor each time a tooth from the gear passes, when the liquid increases or decreases. When the tank is level I can calculate the volume. Using r^2arcCos((r-h)/r)-(r-h)sqrt(2*r*h-h^2) were r = radius and h is height from the bottom of the semicircle to the liquid if it falls below the semicircle. I think I am out of depth on this. I'm in my mid fifty's and math never came easy to me.So any help in any way would appreciated. Does
anyone have a formula for this? The attached drawing may help.

Thank you for any and all help,

Ken

P.S. I have two sensors, One X and one Y
• Dec 8th 2012, 01:55 PM
skeeter
Re: Find the volume of liquid when the tank isn't level
• Dec 8th 2012, 03:29 PM
Ken661
Re: Find the volume of liquid when the tank isn't level
skeeter, Should I delete the post in in the trigonometry forum and leave it in the geometry forum or leave it in trigonometry forum and delete it in the geometry forum?
I am new to this.

Ken
• Dec 8th 2012, 05:44 PM
skeeter
Re: Find the volume of liquid when the tank isn't level
leave the first one.
• Dec 29th 2012, 10:15 AM
Ken661
Re: Find the volume of liquid when the tank isn't level
Hello,

To expand on this question, . I built a level sensor. I am looking for a formula that will give me the volume of the tank if the tank isn't level. Let me explain what I have. The way it works is this.
The sensor has a float tethered to a take up spool. the spool has a gear attached to it so as the float risers or lowers a hall effect sensor counts the number of teeth that pass. This number is then passed on to a microprocessor. And from the count I can now determine the volume in the tank if the tank is level. In the sensor I have two accelerometers, one for the X axis and one for the Z axis. These will give me the amount the tank is off level in degrees in both directions. The formula I am looking for is to find out the actual volume in the tank. I've attached a PDF drawing in a previous post that may help in what I am trying to do. If anyone can't help me or point me in the right direction, I would be most appreciative.

Best regards,

Ken