Hanna salinity tester The HI98319 Waterproof Salinity Tester is a simple, accurate and economical way to determine the salt concentration in saltwater aquariums. HI98319 can measure salinity up to 70.00 g / L (ppt). Results are displayed in g / L (ppt), practical units of salinity (PSU) or specific gravity (S.G.) on a large dual-level LCD display also...