PH Meter Digital 0.01 High Precision Water Quality Tester with 0–14 pH Measurement Range for Aquarium, Swimming Pool, Drinking Water, RO Systems, Spas, and Hydroponics Note: Batteries and calibration powder are not included. This pH meter is suitable for household, laboratory, and general-purpose use—including testing drinking water, swimming pools, aquariums, food-related applications, reverse osmosis (RO) systems, spas, and hydroponic systems. Specifications: - Measuring Range: 0.00–14.00 pH - Resolution: 0.01 pH - Accuracy: ±0.01 pH - Power Supply: 2 × 1.5V LR44 batteries - Automatic Temperature Compensation (ATC): 0–50°C (32–122°F) - Dimensions: 15 × 2.5 × 1.3 cm (6 × 1.1 × 0.5 in) - Net Weight: 52 g (1.83 oz) Calibration Instructions: 1. Turn on the pH meter and rinse the electrode with distilled water. 2. Immerse the electrode in pH 6.86 standard buffer solution. 3. Press the “CAL” button and wait until the display stabilizes at 6.86 pH. 4. Rinse the electrode with distilled water and gently dry it. Then immerse it in pH 4.00 standard buffer solution. 5. Press the “CAL” button and wait until the display stabilizes at 4.00 pH. 6. Rinse and dry the electrode again, then immerse it in pH 9.18 standard buffer solution. Verify the reading falls within 9.17–9.19 pH. Calibration Powder Information: Each packet contains pH standard solid buffer material. Dissolve in distilled water as directed to prepare 250 mL of standard calibration solution. Follow the specified dilution ratio precisely to ensure calibration accuracy. Precautions: - The pH probe contains glass and is fragile. Avoid impact or dropping. - After use, gently blot excess moisture from the probe with absorbent paper. - The device is factory-calibrated. Recalibration is only required under the following conditions: • After extended use since last calibration • After frequent or intensive electrode use • When high measurement accuracy is critical