This digital PH meter is widely used in aquarium, swimming pool, school laboratory, fishing industry, aquaculture, food & beverage processing and much more! It adopts advanced technology and imported components, greatly reduces the volume and costs, maintains a existing good quality. Measuring PH Range: 0.0 - 14.0 pH Resolution: 0.1 pH Accuracy: +/- 0.1 pH (20 C), +/- 0.2 pH Operating Temperature: 0 - 50 C (32 - 122 F) Kindly note: 1. This product should be part of the waterproof, some not waterproof, please be careful. 2. If it"s not used for a long time, pls calibrate it. PH Calibration Steps: 1. immerse the electrode in PH 6.86(under the temperature of 25 C)standard buffer solution of phosphate and gently shake the eletrode. 2. regulate the trimmer with a screwdriver until the buffer solution value corresponding to the measurement temperature is obtained. 3. immerse the electrode in PH4.01 or PH 9.18 the standard buffer solution of borax. 4. after about one minute, until the buffer solution value corresponding to the measurement temperature is obtained. Package: 1 x Digital PH meter 1 x Calibration Adjustment screwdriver 2 x Pouches of calibration buffer solution 3 x AG13 Button Cell Batteries (installed) 1 x User instruction 1 x Plastic Case **Warm Tips**: Buy In Confidence and satisfaction. Visit our store for more amazing products: http://www.amazon.com/shops/lemonbest