[Convenience use] 5 seconds know the water quality, accuracy, faster. This Combo set of TDS PH EC Temperature. [durable model] PH Pen have AUTO CALIBRATION function, no need any kind of screwdriver to calibrate the pH tester pen. TDS pen have Lock auto shut off function. [Pocket Portable] Small size but suitable for testing pH balance of drinking water, swimming pool, aquarium, reverse osmosis system, spa, or hydroponics. [Wide Application] Ideal for home and laboratory pH testing, including drinking water, electroplating liquid, boiler water, water in aquarium, swimming pool water, photographic flushing fluid, well water, deep ground water, aquaculture, food processing and more. Application: production and consumption of pure water, tap water, well water, sea water, aquarium, swimming pool water, soil, aquaculture, food processing, etc. How to measure Prepare Remove the protective cap from the portable player. Continue reading Stabilize Press the ON button / OFF to turn on the device Immerse the electrode in the target solution ensuring that the entire electrode is submerged Gently swirl the solution and wait for the value to stabilize The LCD screen will display the result. How to storeRinse the electrode with distilled water and allow to dry. PH meter Measurement range: 0.00 - 14.00 pH Resolution: 0.01 pH Accuracy: 0.01 pH Automatic temperature compensation: 0 - 60/32 - 140 Calibration: two-point automatic calibration button Coin cell: 2 x 1.5V LR44 (keep using more than 500 hours) Dimension: 155mm*31mm*18mm TDS meter Latch function - easy to read and record, press HOLD button then remove from test solution. 4 Display Modes: Press SHIFT key: TDS - ppmC, EC - s/cmC, TDS - ppmF, EC - s/cmF. not exhaust. Measurement range: Conductivity: 0 - 9990 s/cm TDS: 0 - 9990 ppm (parts per million) Degrees Celsius: 0.1 - 80.0C, Fahrenheit: 32.0 - 176.0F Accuracy: 2% Size: 154 x 30 x 14 mm Scope of delivery: 3 piece (PH meter + TDS/EC water quality detector + test paper)