1. Regularly check the material: Plastic + Metal 2. Dimensions: Approximately 7.1 x 4.6 x 1.2 inches (including 1 V x 1 A battery) 3. Package weight: 220 grams 4. Instructions: - pH measurement (battery not included): - Measured value/Neutral value/Acidity value: First, turn the knob in the PH direction until you hear a click. Gently clean the metal rod with fine - sandpaper to remove scale. Rinse the test rod with clean water, and then wipe it with a tissue or a clean cloth, etc. - (1) Insert the test rod into the neutral solution at the black position. - (2) The pointer will move slowly. Wait for the pointer to stop swinging (about 3 - 5 minutes) and then it will return. - CL measurement (battery included): - 1. Find the adjustment point: - A. Insert one 1.5V "AA" alkaline battery. - B. Turn the knob in the CL direction until it can no longer be moved. (The transparent metal rod at the black position, the water should be a standard solution with a CL value of 1.5 PPM) Repeat this process. Gently stir the water with the metal rod, and then slowly adjust the knob to the right until the pointer points to the known standard CL value. The pointer moves to the right and stops at a letter between A and E. This letter is the adjustment point. - 2. Measurement: - A. Set the pointer to the "set point" position.