The differential refractometer has been used as an effective instrument for chlorinity determination. Results obtained through its application have been compared with those derived from the use of less sensitive refractometers and with those obtained from specific conductivity measurements. The advantages of differential refractive-index measurements when applied to water in an estuarial brackish marsh basin are demonstrated....
Williams, Hulen B., Vincent Farrugia, Anthony Ekker, and Elard L. Haden. 1964. "Chlorinity determination in estuarine waters by physical measurement." Journal of Marine Research 22, (2). https://elischolar.library.yale.edu/journal_of_marine_research/1028