Get Hanna and test with confidence! Designed to bring simplicity to salinity testing during the any process, the HI98319 Marine Salinity Tester measures conductivity (EC) to determine the salinity of natural and artificial seawater. Within seconds, the salinity and temperature are digitally displayed on the LCD. Displays results in parts per thousand (ppt), Practical Salinity Units (PSU), or specific gravity (S.G.). Comes with all the necessary solutions and batteries- everything you need to get started measuring right away. Ideal for testing salinity in aquariums, field, and industrial settings. **For best results, please calibrate monthly.**. {To ensure accuracy of measurements: Use fresh calibration standards for each calibration. Rinse the tester with purified water and dry off with a soft tissue before calibrating or taking measurements. Calibrate monthly with regular use or more often with frequent use. Inspect the tester to see if foreign material is detected in the openings housing the electrodes. A more thorough cleaning may be made using a non-abrasive detergent, and a soft material such as cardboard, to dislodge the material. Rinse thoroughly with a steam of running tap water and jetting the steam through the opening. Shake excess water and rinse in purified water. Dry off and recalibrate the tester before using. Store with the protective cap on.} *Remember the black button to change the settings is underneath the battery cover* Care and Maintenance To ensure accuracy of measurements: Use fresh calibration standards for each calibration. Rinse the tester with purified water and dry off with a soft tissue before calibrating or taking measurements. Calibrate monthly with regular use or more often with frequent use. Inspect the tester to see if foreign material is detected in the openings housing the electrodes. *Rinse thoroughly. *Store with the protective cap on.