Non-contact Level Switch

If you visit any of your local industrial electrical suppliers (or visit thier web sites), you can browse various catalogues by Allen-Bradley (Rockwell Automation), Siemans, Cutler-Hammer, etc... All of these manufacturers carry various types of non-contact level sensors (I believe I have even seen one that measures density when attached to the tank wall - sounds like what you need). Anyway, check it out, and please post your solution (I work for a Dairy, and various ideas that work are always good to have in your back pocket). Good Luck.

The for-sure sensor is a sonic level sensor. It mounts out over the tank and uses "radar technology" for the level indication. I use to work out at one of the oldest phosphate mines in Utah, it covers 25 sq miles of evaporative pounds. The grow salt and potash for furtalizer. Everything is conveyord into process tanks for mixing. On these tanks we found the overhead sonic sensor works the best for your level control.

I have been down this road. I suspect your tank is strainless steel and drilling a hole through the side to insert a level indicator creates a host of problems. An better method would be to insert down from the top of the tank a 2" PVC pipe with a cap glued onto the bottom. Locate the pipe away from the side of the tank a couple of inches and secure the pipe. The bottom of the pipe should be about 4" below the level of milk in the tank. The sensor you will be using will slide down inside the pipe down to the level you require. Level adjustment can be changed by moving the sensor up or down. The sensor to use is made by EFECTOR the part number is KB-2020-ABOA/NI this is a capacitive proximity switch with a voltage rating of 20 to 250 volt AC or DC. This is a cost effective method that will work.

inductive or capacitive proxie switch will do just fine