Rhodamine B (RhB) as a dye tracer is widely used both in laboratory scale and in-situ studies about determination of wastewater plumes' movement and their dilution characteristics in marine environments. RhB added salt (mainly NaCl) water solutions are used on brine outfall laboratory physical model experiments. Some of the experiments in laboratory tanks can be conducted via taking samples inside the discharged brine jets. Taken samples can be measured by optical methods such as ultraviolet visible spectrophotometry for determination of dye tracer concentrations and dilution levels. However, absorbance specifications of a dye tracer, like RhB, might be affected by high concentrations of NaCI in discharge solutions.