TDS-3 Drinking Water Quality Meter Digital Tester Temperature PPM Test Meter Pen Analyzer for Measuring Drinking Water, Hydroponics, Aquarium, Po-TDS-3 Drinking Water Quality Meter Digital Tester Temperature PPM Test Meter Pen Analyzer for Measuring Drinking Water, Hydroponics, Aquarium, Pool and Spa-Product description: Remove the pen cover and turn on the ON switch; Put the pen into the test solution, the height of the solution should not exceed 2cm; Swirl the pen in the solution, once the reading is stable (2-6 seconds), the TDS value will show on the screen, then press the HOLD button to lock the value. After use, dry the water on the pen tip, rinse it with pure water, and close the pen cap. Precautions for use: Avoid immersing the TDS pen in water, avoid direct sunlight, keep away from high temperatures, and avoid strong shocks and drops. Range of product use: Test whether the quality of tap water, purified water, and mineral water meets state-formulated drinking water standards: tap water is less than 300 ppm, l pure water is less than 50 ppm (national standard) and mineral water is from 100 to 200 ppm. Specifications of the test pen are as follows: Wide measuring range → capable of measuring 1-9999PPM. Wide application temperature range → work at 0-50 degrees, can be stored at -30 degrees. LCD display window → large LCD screen Waterproof design, easy to see, durable Long battery life → use 2 x CR1620 3V batteries, can be used for more than 3 years, 10 minutes without auto-off function, save battery Reasonable design → The electrode of the pen tip can be directly inserted into the measured aqueous solution for measurement, and the pen cover can also be used as a container for the measured aqueous solution, which is extremely practical. Fast measurement → Measurements can be performed in 5 seconds thanks to the compact bare sensor element. Hig