Seawater Refractometer RHS-100ATC 0-10% Salinity 1.000-1.070 Salt Specific Gravity Seawater Salinometer For Aquarium This salinity refractometer can be used to measure the salinity of general corrosive liquid more efficiently,especially useful for aquarium and marine applications.With high-quality optics and a smooth focus,made of aluminum alloy.It can replace the hydrometer for easier,more accurate measurement.The internal optical lens with a high refractive index forms a precision optical system.It is convenient for children and adults,ideal for aquariums,marine monitoring,agricultural,gardening&educational purposes. Product features The Salinity Tester is better than traditional hydrometers and more cheap than digital refractometer. The Salinity Refractometer with dual scale.The scale range of this refractometer is salinity of 0~100(1=1 PPT=1000PPM,PPT means"parts per thousand",PPM means"parts per million"),it also shows the corresponding specific gravity range 1.000 to 1.070. Easy to carry and easy to use,no batteries required.just 2-3 drops of solution and a few seconds,you'll get accurate readings,and under the guidance of the user manual,you'll learn how to easily calibrate and use the refractometer. With ATC function,the refractometer is equipped with automatic temperature compensation part inside,which minimizes the effect of the temperature. How to Use Calibration:just 2-3 drops of fresh water or distilled water.Turn the calibration set screw until the blue line is on zero. After calibration,clean the prism with soft cloth.use the dropper to take a sample of wort and put it on the prism. Align the prism assembly with the light source,look into the eyepiece and you can get the reading. Package Refractometer x 1 Plastic Pipette x 1 Mini Screw Driver x 1 User Manual x 1 Cleaning Cloth x 1 Plastic Box x 1