The Extech RF11 is a refractometer for measuring the concentration of industrial liquids and sugar in fruit juice. It is compact and easy to use. The RF11 requires only 2 or 3 drops of solution and provides accurate and repeatable measurements on an easy-to-read scale. Prism and lens with easy focus adjustment and automatic temperature compensation from 10 °C to 30 °C (50 °F to 86 °F).