I am trying to automate silos by being able to track their material levels. These silos are free standing on 4 legs, cylindrical shaped, and are 21 feet high. They have two compartments, (divided down the middle) holding sand in one and dry cement in the other. They are electrically run and have a vibrator on them for the emptying of the machine. These silos are mobile and are moved from job site to job site (they mix mortars, stuccos, and grouts).

I have looked into using an ultrasonic route, however the price has ended up around $5000 per machine, once I have all the parts. I don't think a probe of any kind will work because of the shape material empties in (conically) and because of the inaccuracies that are likely to occur (due to the conical shape inside). I looked at another posting on this forum and saw that load cells could work, yet I have just begun to research that idea. I am thinking I will have a problem in using load cells because I am dealing with a split silo (the two different compartments inside)

Is there anyone who has enough knowledge of automating silos that can help me apply the technology that is out there to my problem? What's the best way to do this? ■