Just remove the protective cap and immerse the PH meter electrode in the solution and press the button to be measured. Pocket Size PH Meter is the ideal test kit for home and laboratory uses. The Tester has a sensitive electrode sensor, Accurate PH levels can be read. Features: [Accuracy]The digital PH meter has a measuring range of 0.00- 14.00PH, an accuracy of 0.05PH. Extra 3 sets of PH calibration powder make it more accurate than test strips. [LCD Display]The water quality test has a large and easy-to-read LCD screen. It only takes a few seconds for your result to appear on the screen. [Automatic Temperature Compensation]Since the PH meter has built-in (ATC) automatic temperature compensation, It is no longer necessary to pay attention to the temperature of the test liquid. [Portable]This portable size instrument allows you to carry it around easily in your pocket and do your measuring anywhere. [Widely Applicable]Suitable for aquarium, pool, pond in a garden, bathtub to test the levels of alkalinity in your drinking water, urine, RO System, spa, etc. Specifications: Color: Yellow Material: Glass, ABS, Electronic Component Style: Casual PH Range: 0-14 Accuracy: 0.05PH Temperature Compensation: ATC Battery: 2*1.5V Button Battery (Included) Application: Water Occasion: Home, Outdoor Product Size: 15.5*3.1*1.8cm / 6.1*1.2*0.7inch Package Size: 16.7*5.2*3cm / 6.5*2.04*1.18inch Package Weight: 120g / 0.26lb Package List: 1 * Digital PH Meter 1 * 3CPS PH Buffer Powder 1 * User Manual PH Calibration Method: 1.Prepare 250mL distilled or purified water 2.Put the 6.86 calibration powder in the green packaging, stir it thoroughly to dissolve it 3.ut the test pen into the calibration fluid, if it shows data around 6.86, no correction is needed. If the data deviates greatly from 6.86, press and hold the Cal key for 3s and let go. After 5s of automatic calibration, END will be displayed, indicating that the calibration is complete. 4.Use the same method to use 4.00 calibration powder 5.Generally, only two packs of 6.86 and 4.00 calibration powders are needed, and 9.18 calibration powders are not needed. Note: In the following cases, the PH meter needs to be recalibrated 1. It has been used or placed for a long time, and the phenomenon of inaccuracy appears 2. The shelf life of calibration powder is 2 years 3. Can not measure liquids with a pH lower than 2 or higher than 13 4. The temperature must be maintained at 0-50 degrees Celsius, otherwise, it will cause the glass electrode to burst