Salinity is the total mass, expressed in grams, of all substances dissolved in one kilogram of sea water when all carbonate has been converted to oxide, all bromine and iodine has been replaced by chlorine and all organic compounds have been oxidized at a temperature of 480oC. Slide 9 of 13 Salinity is the total mass, expressed in grams, of all substances dissolved in one kilogram of sea water when all carbonate has been converted to oxide, all bromine and iodine has been replaced by chlorine and all organic compounds have been oxidized at a Principle of constant proportion states that the absolute amount of salt in sea water varies, but the relative proportions of the ions is constant. Because of this principle, it is necessary to test for only one salt ion, usually chlorine, to determine the total amount of salt present. Salinity is equal to 1.8065 times chlorinity.
Salinometers determine salinity from the electrical conductivity produced by the dissolved salts.