Elbourn pH Meter: A Digital pH Tester Pen for Water How to Use? Step 1: Remove the protective cap Step 2: Clean the electrode in distilled water and let it dry Step 3: Turn the meter on by pressing the ON/OFF key Step 4: Immerse the pH meter electrode in the solution you want to test Step 5: Stir gently and wait for the displayed pH to stabilize Step 6: After finishing, clean the electrode in distilled water and turn the meter off by pressing the ON/OFF key Product Features Measure Range : 0.00 - 14.00 pH Resolution : 0.01 pH Accuracy : 0.05 pH Calibration: Two Points Automatic Calibration Button Power Supply: 2 x 1.5V LR44 Button Battery (keep using more than 500 hours) Dimension: 155 mm * 31 mm * 18 mm Weight: 50 g Notes 1. Don't touch the electrode with fingers or abrasive, hard tools. Always replace the protective cap after use to keep electrode from drying out. 2. Clean the electrode before and after each use. 3. If the meter cannot seem to be turned on or the display seems to fade, open the battery case and replace the battery (pay attention to polarity), then recalibrate the meter.