The Uniqueness of the Practical Salinity Scale (1978): Testing the Scale with Natural Seawaters

The Practical Salinity Scale (1978) provides a precisely defined, unambiguous method that is universally applicable to all waters for determining salinity, or more precisely the practical salinity, from measurements of conductivity, temperature, and pressure.In the terminology of standards, it is highly desirable to have a scale that is also unique. For example, we would hope that measurements performed on a particular water sample at different temperatures would lead to the same value of the practical salinity. We have investigated this problem by examining the behaviour of natural seawaters from several of the world\´s oceans. We conclude that the PSS provides a unique scale for salinity measurements for these waters within the bounds in salinity.