Tester with 4 Display Modes This advanced water hardness tester combines TDS (Total Dissolved Solids), CE (Electrical Conductivity) and a 3-in-1 digital temperature measurement test pen. This pH meter has 4 display modes to choose from, TDS - ppm and C, EC - s/cm and C, TDS - ppm and F, EC - s/cm and F ( press the button MODE to convert).Luminous alarm function Lock function makes it easy to play and record, press the HOLD button, then remove it from the test solution. PH tester has light alarm function, green backlight with TDS value less than 40; red backlight when the TDS value is over 40.Auto Power Off The pH tester without operation 2 minutes automatic shutdown, so that the battery will not be discharged, a convenient automatic power off function ensures a long battery life.Wide Application This digital TDS tester provides a detailed and accurate report of the quality of drinking or used water for your pets, fish and gardening. Automatic temperature compensation ensures accurate readings in cold and hot water. Note: The data is all measured manually, please allow 1-3cm error, due to the difference in light and display, there will be a certain color difference, the actual object received shall prevail.