The surface tension of an aqueous lithium bromide solution containing an active surfactant (2-ethyl-1-hexanol) was measured over the lithium bromide concentration range 40 less than or equal to C-LiBr less than or equal to 60 Wt % and surfactant concentration range 0 less than or equal to C-SUR less than or equal to 200 ppm. The Du Nouy ring method was employed to determine the surface tension.