[Convenience use] 5 seconds know the water quality, accuracy, faster. This Combo set of TDS PH EC Temperature. Besides, it has the best price, reliable quality, all make it your first water quality test. [How accurate? ] pH resolution is 0.01pH, accuracy 0.01pH.TDS: 0~9990ppm, Conductivity: 0~9990us/cm, accuracy: 2%. It is the same as big brand resolution in Amazon, but Pancellent test only need half price . [durable model] PH Pen have AUTO CALIBRATION function, no need any what type of screwdriver to calibrate the pH tester pen. TDS Pen have Lock &amp; 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 rinsing fluid, well water, deep ground water, aquaculture, food processing and more. Product Little money to know the water quality TDS pH meter set is a professional level water tester. Application: production and consumption of pure water, tap water, well water, sea water, aquarium, swimming pool water, soil, aquaculture, food processing, etc. The Package includes: 1 x PH Meter 1 x TDS Meter 6 x Calibration Packages 1 x Calibration Manual 'user How to measure Prepare Remove the portable player's protective cap Keep reading Stabilize < p>Press the ON/OFF button to turn on the device Immerse the electrode in the target solution ensuring that the entire electrode is submerged Gently agitate the solution and wait for the value to stabilize The LCD screen will display the result . How to store Rinse the electrode with distilled water and allow to dry. Specifications PH meter Measuring range: 0.00 - 14.00 pH Resolution: 0.01 pH Accuracy: 0.01 pH Automatic temperature compensation: 0 - 60/32 - 140 PH meter Calibration: automatic two-point calibration button Button battery: 2 x 1.5V LR44 (continue to use more than 500 hours) Dimension: 155mm*31mm*18mm Weight: 50g TDS meter Lock function - facilitates reading and recording, press HOLD button then remove from test solution. 4 Display modes: press SHIFT key: TDS - ppm &amp; C, EC - s/cm &amp; C, TDS - ppm &amp; F, EC - s/cm &amp; F. 5-minute auto-shutoff feature so the battery won't run out. TDS meter 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% Net weight: 55g Size: 154 x 30 x 14 mm pH meter calibration 1, the calibration powder with 250ml of distilled water or pure water to open. Dip the pH electrode into pH 6.86 mixed phosphate standard buffer and shake gently. 2, press the CAL button, automatic calibration will proceed to the displayed value and the standard buffer solution at pH 6.9 compatible with room temperature. 3, the same as above, the electrode was inserted into a standard buffer solution of phosphoric acid potassium bicarbonate and of phosphoric acid. 4, about two minutes. The displayed value must be within the error tolerance with respect to the pH value of the buffer solution.