Measuring Salinity and Density of Seawater Samples with Different Salt Compositions and Suspended Materials

TL;DR

This paper explores new in situ methods for measuring seawater salinity and density, focusing on indirect techniques using electrical conductivity, sound speed, temperature, and pressure, along with a novel sensor design.

Contribution

It introduces a new electric conductivity sensor design and analyzes joint measurement techniques for assessing seawater properties with solid suspensions.

Findings

Sensor design enables data collection on solid suspensions.

Joint measurement methods improve accuracy of salinity and density estimates.

Tests on water samples with different salt compositions validate the approach.

Abstract

Determining of the solute mass amount in seawater using in situ measurements in seas and oceans remains now an unresolved problem. To solve it, it is necessary to develop both new methods and instruments for measurements. This article analyzes methods for the indirect measuring of salinity and density using parameters that can be measured in situ, including relative electrical conductivity, speed of sound, temperature and hydrostatic pressure. The authors propose an electric conductivity sensor design that allows for obtaining data on solid suspensions along with measuring the impedance of electrodes under various the alternating current frequencies. The authors analyze the joint measurement technique using the CTD and SVP devices in a marine testing area. Based on the results of joint measurements, the authors present tests of water samples of various salt composition for the presence of solid suspensions.