Handheld portable refractometer for Brix (0.0 to 10.0%) measurement of low-concentration juices and low-concentration industrial fluids * Automatic temperature compensation and calibrated with distilled water using a tool-free calibration ring * Ambient light illuminates the scale; no additional power source is required * Sturdy design, made of sturdy Aluminum and not "carbon" plastic * Optical glass prism mounted in all-metal housing for quick temperature equilibrium between sample and prism