5-In-1 Multi-Function Tester One-Click Mode Switching Total Dissolved Solid Value In Water (1-20000ppm) Seawater Salinity Is The Ratio Of The Total Dissolved Solids To The Weight Of Seawater. It Is Usually Expressed In Grams Per Kilogram Of Seawater. Measuring Range: 10.1-200.0ppt High-Definition Backlight, Clear Display Even At Night Test Items:Ph, Salinity Measurement Accuracy:1ppm 1us/Cm 0.01ph 0.01% Salinometer:Multi-Parameter Water Quality Detector Type:Voice Charging 5-In-1 Multi-Function Pen Measuring Range:Salinity:0.00 To 25.00% Ph:0-14 Resolution:1ppm 1us/Cm 0.01ph 0.01% Note:Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Will Not Affect The Use Colour:As Shown Material:ABS Package Contents: 1 * Water Quality Detector 1 * Data Cable 3 * PH Calibration Powder 1 * Chinese And English Instructions Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.