3200 RPM using Kool Mist #77 40:1 ratio, as flood coolant 11 gallon per minute steel and aluminum cutting.

I got a $35 refractometer off ebay. Calibrated it to 0 with distilled water. Right now my flood coolant is reading 2.5 1-30 scale 20 celesus. Most of my tramp oil has been skimmed by a belt.

Is this a correct reading. Can find nothing on what factor Kool Mist used as flood would be. I dont need perfect just a decent number.

Thanks! . R.