Refractometer measures salt content in sea water, pickling-brines, and other applications

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, acetic acid, and vinegar. To operate the device, simply place a drop or two of sample on the prism and read the results.