Large display, different measuring instruments can be selected, only one hand is needed, two in one, practical and affordable. Suitable for home and laboratory pH test applications, such as home drinking water, swimming pools, tap water, spas, laboratories and scientific testing. Chlorine content within the safe measurement range: 1.2-1.7 ppm, pH value within the safe measurement range: 7.2-7.8. Setting accuracy: Before using this tool for the first time, you need to search for the adjustment point of the tester (refer to the instructions). It is an indispensable tool for swimming pools, saunas and spas. Just quickly check the current pH value and chlorine content of the water. Storage method: To extend the service life of the swimming pool tester PC-101 and ensure the measurement Please note: 1. When not in use, please adjust the knob to the off position (adjust it to the PH direction until it can no longer move). 2. Store in a cool, dry place away from direct sunlight. 3. Do not immerse the test stick in any liquid other than swimming pool water or hot spring water. 4. Check the battery level regularly - the tester uses an "AA" 1.5 V alkaline battery