Silo Weight Measurent, Load Cells or strain gauge sensors??

[HSM2010]

I am working on a project where I must measure the Weight of a silo to determine how much product is in it. I am wondering if i should go with load cells at the bottoms of the Silo, or use strain gauges on the side to get a measurement of the weight, accuracy and cost are the 2 biggest factors

Anyone have any advice or suggestions?

 

[danw2]

The side mounted strain gauges are a fraction of the cost of load cells, are much easier to install, but are a fraction of the accuracy of load cells.

 

[controlnovice]

Tried strain gauges, and the accuracy was nowhere where we needed it to be. Plus, the weight would change with the ambient temperatures: sun heating the vessel, cooling at night.

This was about 8-10 yrs ago, so maybe something has changed since then.

If you want accuracy, load cells is the way (weigh) to go, but they will be much more expensive, especially if you need to put flex hoses on the piping.

We are trying something different for our process. We are trying BinMaster's 3D Level Scanner. Other companies produce similar product. It's a ultrasonic (I think) instrument that measures the height (or distance from top) of the product. It takes a 3d 'picture' and can calculate the volume of the product in the vessel. From this, you can calcuate weight.

We are installing 2 as a trial in the next 2-3 months and hope this is the answer.

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[HSM2010]

accuracy is what we are looking for, i will have to lean more towards load cells. That 3D level Scanner sounds cool, I never seen or herd of a device that work such a way, i will deffinetly read up about it.

Thanks guys

 

[quark]

controlnovice,

Seems to be a good idea with some drawbacks. The new technology might be presuming uniform bulk density of entire mass. Calculation of surface contour may help you during normal flow conditions. You may have some control problems with arching and ratholing may reduce the accuracy of measurement. Just for the sake of knowledge, can you throw some light on what kind of precautions you have considered?

 

[controlnovice]

We've considered all of those...and I pushed weigh cells.

But operations doesn't want to pay for weigh cells, so this is the closest best thing.

We're not concerned with level/volume during the process. This is more for inventory, so this solution will be the least expensive...until they realize the above possible issues...

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This is normally the space where people post something insightful.