Accurate and reliable: Due to its advanced microprocessor technology and+/-2% reading accuracy testing, TDS meters are efficient and accurate, and titanium alloy probes have high testing accuracy and reliable automatic temperature compensation (ATC) magnetic field interference in water. Two test ranges are 0-9990 ppm, ppm. The TDS reading will be displayed on the LED screen in PPM (one million parts). A measurement can be completed in 5 seconds. What is TDS: Total dissolved solids, also known as TDS.TDS instrument is a water quality testing tool used for drinking water, drinking water, water filtration and purification systems, such as RO or DI systems, aquariums, hydroponic methods (testing nutrients), swimming pools and spas, commercial and industrial applications, and more. The TDS meter digital water tester is very suitable for checking the quality of tap water and knowing when to replace the filter. Why care about TDS: High TDS levels can change the taste of water, making it salty, bitter, or metallic. High levels of TD also indicate the presence of toxic minerals that are harmful to health. High TD can harden water, causing spots on pipes, dry hair, tableware, and making kitchen utensils useless. The ppm meter can help you avoid the above issues. According to the EPA, the maximum TD concentration in drinking water is 500 ppm. type: A-Without Battery (2 x LR44 button batteries) Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Material: plastic colour: White+Black Package Contents: 1 x Tds Meter