Digital Tester 169E ORP/Redox Tester ORP Tester Potential Positive and Negative ORP Meter High Precision Tester Meter FG05 Oxidation-Reduction Potential (ORP) represents the oxidation potential of a solution. The ORP value measures the redox ability of a solution, with units in mV. An ORP meter is specialized equipment for testing the redox potential of solutions. The instrument features a waterproof enclosure design with an IP55 waterproof rating. The electrode is replaceable. Includes a data hold function to facilitate measurement, reading, and recording. This device is a negative potential (O.R.P) meter. Incorporates advanced technology and components, significantly reducing size and cost while maintaining original quality, making it widely used for applications such as functional energy water purifiers and negative potential energy cups requiring determination of negative potential values. Main technical specifications: Measuring range: 0 to ±1999 mV Resolution: 1 mV Accuracy: ±5 mV Battery: 4 x 1.5V (AA batteries), not included Operating temperature: 0°C to 50°C Calibration: 1-point calibration Instructions: 1. Remove the protective cover. 2. Press the "ON/OFF" button to power on. 3. Place the electrode into the test solution and gently shake until the display reading stabilizes. 4. Press the "HOLD" button to lock the current measurement value. To take a new measurement, press "HOLD" again to release the hold function. 5. After use, turn off the device, rinse the electrode with distilled water, and place it back into the protective sleeve. Battery replacement: If the display appears dim or unclear, replace the batteries. To replace, unscrew the battery compartment cover, insert new batteries observing correct polarity. Calibration procedure: 1. Soak the electrode in distilled water for several hours before first use. 2. Immerse the electrode in calibration solution and stir gently. 3. Adjust the trimmer using a small screwdriver until the LCD displays 265 mV. 4. Rinse the electrode with distilled water and gently blot dry with filter paper. Color: White + Green Material: ABS + electronic components Dimensions: 18.8 cm x 3.5 cm x 3.5 cm Package contents: 1 x 169E ORP Tester 1 x English manual Note: Light and screen differences may cause slight variations between the product color in images and actual item. Measurement error allowance is ±1–3 cm.