Seawater salinity is the ratio of total dissolved solids to the weight of seawater and is expressed in grams per kilogram (ppt). Measuring range: 10.1 to 200.0 ppt. OneClick Mode Switching enables fast, simple changes between measurement modes. 5In1 MultiFunction Tester provides five measurement capabilities in a single instrument. Total Dissolved Solids TDS in water is displayed from 1 to 20000 ppm. Key benefits Delivers reliable salinity readings for seawater and marine environments. Simplifies operation with a single button to switch modes. Combines multiple water quality measurements in one device, reducing equipment and space requirements. Wide measurement ranges support typical seawater and TDS testing needs. Performance and attributes Measurements are presented in standard units: salinity in ppt and TDS in ppm. Designed to support quick and straightforward water quality checks in marine settings. Use scenarios Reef aquarium maintenance: regularly monitor salinity to maintain stable conditions for corals and marine life. Marine research or field work: perform onsite testing of seawater samples for salinity and total dissolved solids. Aquaculture and hydroponics: track TDS levels to ensure growing and rearing conditions.