Product Instructions: 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 2 cm; Stir the pen in the solution, after the reading is stable (2-6 seconds), the TDS value will be displayed on the screen, then press the HOLD key to lock the value. After use, dry the water on the pen head, rinse with pure water and cover the pen cover. Precautions for use: Avoid immersing the TDS pen in water, avoid direct sunlight, keep away from high temperatures, and avoid violent shock and fall. Product Use Range: Test whether the water quality of the Tap, purified water, and mineral water meet the drinking water standards formulated by the state: tap water below 300 ppm, pure water below 50 ppm (national standard), and mineral water between 100 and 200 ppm. The specifications of the test pen are as follows: Lightweight and pocket-sized Weighing 28 grams, it is a small and light portable TDS instrument on the current market, with a length of 14.2 width of 2.3 thickness of 1.3 (CM). Wide measuring range Capable of measuring 1-9999PPM. Wide application temperature Works at 0-50 degrees and can be stored at minus 30 degrees. LCD display window Large-screen LCD display. Waterproof design, easy to see, durable Long battery life Using 2 CR1620 3V batteries, it can be used for more than 3 years, and the automatic shutdown function is not used for 10 minutes to save battery life. Reasonable design The pen tip electrode can be directly inserted into the measured aqueous solution for measurement, and the pen sleeve can also be used as a container for the measured aqueous solution, which is extremely convenient. Fast measurement Thanks to the compact bare sensor element, a measurement can be completed in 5 seconds. High precision 1% error, the titanium alloy probe has high water measurement accuracy and is immune to magnetic interference in water. Automatic temperature compensation can automatically convert the indicated value to the indicated value at 25 degrees. Package List: 1 TDS Pen.becomeveryrich