Portable Refractometers measure the concentration of Sugar, Salt, Glycol, Lubricants, Battery coolant and more. Features: Easy to operate refractometers provide accurate and repeatable measurements on easy to read scales. Automatic temperature compensation models available for sugar, salt, lubricants, cutting fluids, and battery coolant. Requires only 2 or 3 drops of solution. The prism and lens with a simple focus adjustment provides repeatable results. Complete with carrying case and calibration screwdriver. Salinity refractometer measures the concentration of dissolved salt in water.