Refractometer features Automatic Temperature Compensation (ATC), which makes manual temperature corrections unnecessary

Double scale in parts per thousand and specific gravity. Measures salt content in sea water, aquariums, breeding ponds, or pickling-brines. While the scale is calibrated for sodium chloride, it can also be used for calcium chloride, barium cobalt, magnesium, cesium, potassium, sodium chloride, cupric sulfate, potassium iodide, citric acid, and acetic acid (vinegar), when tested against a known standard. To operate, simply place a drop or two of sample on the prism and read the results.

Specific gravity: 1.000 to 1.070