Brix
Although Refractive Index (RI) is the right technology for brix and liquid concentration measurements. It is NOT good for Lime Kiln application. The reason is that only dissolved material effects RI (sugar, acid, caustic, chemical) and since lime is NOT dissolved, RI does not pick it up. On the flip side, an application were this “side effect” IS helpful is in a sugar pan application. By using microwave to determine total solids AND refractive index to measure dissolved material only. You can calculate what is crystallized.
As far as the debate between inline refractometers there are inexpensive ones, but there is only one that works, and works well in “less then perfect” conditions.
The K-Patents is more robust, will less maintenance, no lamps to replace, no drifting, and no influence by flow changes, etc. It is pretty clear when you put them head to head!