Strain gauge for silo level recommendations.

Customer does not want any silo penetrations. Hates level sensors on top of silos. No capacitance sensors either.
Would be great if it had Ethernet CIP connection (Logix 5000), but not necessary.


I though Keyance had them but I saw our rep today and he said they don't.


Thanks,

check with Hardy they may have what you need depending on the silo type

industrial load cells for silos
https://www.minebea-intec.com/us/load-cells/vessel-and-silo-weighing-500-kg-520-t


electronics for the load cells above:
bottom of page 3 says you can get Ethernet/IP
https://www.minebea-intec.com/share...eighing/weighing_electronics/ds_pr5230_en.pdf

We have one on a powder silo, but I'd have to check what it is.
It reacts very, very slowly though. The level can take a few hours to peak after taking a delivery. It's fine for what we need, as it's just a rough guide as to when more needs ordering and it's not critical for the process.

I think you are after the kind of strain gauges that are attached to the supporting beams of the silo, i.e. it is not a load-cell per se.
Search for "silo strain gauge" and you will find plenty.
Since these strain gauges do not weigh exactly (in reality it measures compression or tensioning of the beam that it is attached to), you have to calibrate them after the installation with a full cycle empty-to-full.
There is also an issue with the supports for the silo. If there are several silos next to each other and the supports are shared, it may be difficult to find a beam that is only affected by the single silo which the strain gauge shall measure.

Puddle said:

We have one on a powder silo, but I'd have to check what it is.
It reacts very, very slowly though. The level can take a few hours to peak after taking a delivery.

Click to expand...

Sounds odd.
A strain gauge reacts practically instantaneously.
It can be necessary to add a filter since it may be too sensitive.
Maybe you actually have such a filter, and it is cranked up to maximum dampening ?

JesperMP said:

Sounds odd.
A strain gauge reacts practically instantaneously. ...

Click to expand...

I have a vague memory (from Material Science 101, maybe?) of something called anelastic strain, that might account for the noted effect.