Advanced CPU: Automatically calibrated per temperature, 0 - 9990 ppm TDS Measurement Range with 1 ppm ResolutionHold Button: Holds measurement value when moving out of water for convenient reading and recordingTemperature Button: Test water temperature, 31 - 200 F degrees, 1 F degree resolutionAuto-off function: shuts off automatically after 10 minutes of non-use to conserve batteriesComes Handy when needed: Comes with leather carrying case and clip, ideally to carry around and test water quality at various places

• A TDS meter (aka ppm pen, nutrient tester, tads stick) is an inexpensive and convenient digital tool to instantly check your overall water quality.
• TDS = Total Dissolved Solids, which is any salt, metal or mineral in the water. With the push of a button, the TDS meter can tell you your overall water purity level, which will be displayed on the screen in ppm (parts per million).
• The lower the TDS level, the purer the water, with 0 ppm being pure H2O. The TDS meter is great for checking your tap water quality, or knowing when to change a filter. (The meter does not test for biological contaminants.)
• The TDS meter is a rugged model that includes a protective carrying case. Pressing on the temperature button allows you to test the temperature of the water (please allow 1-2 minutes for an accurate reading for the temperature compensation).
• This is the world's most popular handheld TDS meter for both industry professionals and household use.
• The TDS meter is a great tool for drinking water, water filtration and purification, colloidal silver, hydroponics (test your nutrients), aquariums, RO/DI systems, pools and spas, commercial and industrial applications and more.