Digital Tester 169E ORP/Redox Tester Potential Positive and Negative ORP Meter High Precision FG05 Oxidation-Reduction Potential (ORP) represents the oxidation potential of a solution. The ORP value measures the redox ability of a solution, expressed in millivolts (mV). This ORP meter is specialized equipment for testing the redox potential of solutions. The instrument features a waterproof enclosure with an IP55 rating. The electrode is replaceable. Includes a data hold function for convenient measurement reading and recording. Designed for measuring negative potential (O.R.P). Incorporates advanced technology and components, reducing size and cost while maintaining quality, making it ideal for various applications. Suitable for use with water purifiers and other devices requiring negative potential measurement. Main Technical Specifications: - Measurement Range: 0 to 1999 mV - Resolution: 1 mV - Accuracy: 5 mV - Battery: 4 x 1.5V (AA batteries), not included - Operating Temperature: 0C to 50C - Calibration: Single-point calibration Operating Instructions: 1. Remove the protective cover. 2. Press the "ON/OFF" button to power on the device. 3. Immerse the electrode into the test solution and gently shake until the display stabilizes. 4. Press the "HOLD" button to lock the current reading. To resume measurement, press "HOLD" again to release the hold function. 5. After use, turn off the device, rinse the electrode with distilled water, and replace the protective sleeve. Battery Replacement: If the display becomes dim or unclear, replace the batteries. Unscrew the battery compartment cover, insert new batteries observing correct polarity, and secure the cover. 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 calibration trimmer using a small screwdriver until the display reads 265 mV. 4. Rinse the electrode with distilled water and 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: The package includes only the items listed above. Other products are not included. Note: Lighting and display settings may cause slight color variations between the image and the actual product. Measurement error is 13 cm.