"Product Ruolan, KIKI founder. The R&D center is located in Stockholm, Sweden and is made up of Swedish independent designers and co-designers to provide creative support to the brand. Ruolan is mainly engaged in household products, and also manages life accessories and other categories, covering daily life, integrating research and development, design, supply and sales, providing practical products and vital inspiration for life. people's daily life. Be sure to add water according to the required ratio, otherwise it will affect the calibration accuracy and increase the error Calibration powder: pH standard solid substance. It can be used after adding water. Suitable for the calibration of any type of pH meter. Each packet can prepare a 250ml standard solution. Calibrate in the order of 6.86, 4, 9.18 Read more Tip: The PH probe is a glass product and it is a fragile product. Please don't bump into things. Once the damage is not replaceable, you need to protect the probe. After use, use absorbent paper to gently absorb the water from the probe. Open the cover of the pen, the number may float, this is a normal phenomenon, because the probe contact with the air may cause the number to float The pH meter has been calibrated before delivery, the buyer does not need to re-calibrate after receiving the goods In the following cases, the pH meter should be recalibrated: 1. It has been used for a long time after calibration; 2. Special electrode use frequently; 3. Measurement accuracy requirements are relatively high. Read more Battery installation: If the brightness of the backlight drops significantly or the display value is blurred, the battery needs to be replaced. When replacing the battery, just pull out the battery compartment and replace it. Note the polarity of the battery. Read more Standard configuration: 1XPH meter 3X calibration powder 1 gift box. 1 instruction manual. Read more"