TDS Meter: TDS meter measuring principle is to measure the electrical conductivity of water and indirectly reflects the TDS value PPM Meter: Test the impurities in water such as some elements of soluble salts, ionic organic compound, heavy metal ion, etc, offering much convenience for you and your families to get a more clean water Water Quality Tester: It supports hold function that can save measurement results for easy reading and record Total Dissolved Solids Meter: Automatic power-off function allows it to power off after 5 minutes without any in order to save power Wide Application: The TDS meter can be widely used for aquarium, beverages, quality control, fish hatcheries, food processing, laboratory, schools, colleges, swimming pools, etc