Getting WEIGHT (kg) from LEVEL (m)

Hi,

Really need your advice, is it possible to get WEIGHT (kg) from tank that has one sensor (ultrasonic) that measure level(m) on this tank?
Someone was tell me, to get weight (kg) from level parameter (m) you need calculated it with liquid density / gravity?
I used AB SLC 500 to get weight (kg) something like this:

Compute

DEST N7:0

Expression (F8:15 * x) * f8:0

Where:

N7:0 = Weight (Kg)
F8:15 = Level (in meter)
X = constanta
f8:0 = specific grafity

Somebody knows with this?
Thanks in advanced

This may help you distinguish the differencs in weight, specific density, specific gravity, mass etc.
http://www.engineeringtoolbox.com/density-specific-weight-gravity-d_290.html

There are numerous ways to do this, depending on what factors are known. If you know the specific weight of the material and volume of the container it will be a straightforward calculation.

Lets say you use the level position to calculate volume in cubic meters and the material is water i.e. it will be "volume" x 7.74. 7.74 is the specific weight of water.

Hope this helps.

In order to derive weight from level you also need to know the temperature of the material in the tank. The density of the material will be affected by temperature and you will need to compensate for this.

Andybr

For your formula to work, it will have to be a vertical cylindrical tank. Otherwise the weight of the contents is not linearly proportional with the depth.

The 'X' in your formula will have to be the area of the tank in square meters multiplied by the density of water in kg/m^3.

Make sure that the value from your ultrasonic sensor represents the depth of the fluid in the tank and not the distance between the sensor and the surface of the fluid.

Deer said:

Hi,

Really need your advice, is it possible to get WEIGHT (kg) from tank that has one sensor (ultrasonic) that measure level(m) on this tank?
Someone was tell me, to get weight (kg) from level parameter (m) you need calculated it with liquid density / gravity?
I used AB SLC 500 to get weight (kg) something like this:

Compute

DEST N7:0

Expression (F8:15 * x) * f8:0

Where:

N7:0 = Weight (Kg)
F8:15 = Level (in meter)
X = constanta
f8:0 = specific grafity

Somebody knows with this?
Thanks in advanced

Click to expand...

Weight = Litres * S.G

http://www.wemactanks.com/tankcalc.htm

That is a link to a web page to derived litres based on inches of water column.

From this web page, you input the tank dimensions, wheather a horizontal or vertical tank, and can derive a table of 1" increments = Litres.

Where portions of the tank walls are not straight, a lookup table can be used based on the breakpoints calculated from the web page.

Only unkown is specific gravity, and many factors can affect that. If the material to be 'weighed' is batch based, different ingredients added at different times this method will not work well.

But if you know the S.G of the final product, and that product is very stable in the tank, no agitation, the above formula should.

How accurate do the weight readings need to be ? 10% , 1%, 0.1%?
Ian

everybody thanks for your inputs, it's very useful for my knowledge,cheer