The Apera SX751 (AI469) is a professional handheld 8-in-1 water-quality meter designed for commercial cultivation, hydroponics, fertigation, and water-treatment applications. It measures pH, oxidation-reduction potential (ORP), dissolved oxygen (DO), electrical conductivity (EC), total dissolved solids (TDS), salinity, resistivity, and temperature using four dedicated interchangeable electrodes. Automatic electrode recognition detects which probe is connected and switches to the appropriate measurement mode, reducing manual adjustments during routine testing.
The complete kit includes a 201T-S pH/temperature electrode, a 301Pt-S platinum-ring ORP electrode, a 2301T-S platinum-black conductivity/temperature electrode, and a DO500 polarographic dissolved oxygen electrode. The conductivity probe measures across a wide range of 0–200 mS/cm, while the DO electrode requires approximately five minutes to polarize and reaches 90% of its final reading within 30 seconds of immersion. Its IP57-rated housing, digital filtering, and onboard storage for 400 measurement records make it suitable for field testing across multiple nutrient reservoirs, water sources, and irrigation zones.
• Product Type: Handheld multiparameter water-quality meter kit
• Brand: Apera Instruments
• Model: SX751
• SKU: AI469
• Measurement Parameters: pH, ORP, dissolved oxygen (DO), electrical conductivity (EC), TDS, salinity, resistivity, and temperature
• Number of Included Electrodes: 4
• pH Electrode: 201T-S combination pH/temperature electrode
• ORP Electrode: 301Pt-S platinum-ring electrode
• Conductivity Electrode: 2301T-S platinum-black conductivity/temperature electrode
• Conductivity Cell Constant: K = 1.0
• DO Electrode: DO500 polarographic dissolved oxygen electrode
• Conductivity Measurement Range: 0–200 mS/cm (0–200,000 µS/cm)
• Dissolved Oxygen Range: 0–20.00 mg/L
• DO Polarization Time: Approximately 5 minutes before measurement
• DO Response Time: Reaches 90% of its final reading within approximately 30 seconds of immersion
• Electrode Recognition: Automatically detects the connected probe and selects the corresponding measurement mode
• pH Calibration: Automatic 1–3-point calibration
• EC Calibration: Automatic one-point calibration
• Temperature Compensation: Automatic compensation for relevant measurement parameters
• Digital Filtering: Proprietary filtering technology designed to improve response time and measurement stability
• Data Storage: Up to 400 measurement records, with storage and recall functionality
• Additional Functions: Electrode self-diagnosis and automatic power-off
• Water and Dust Protection: IP57-rated housing, designed for dust-tight protection and temporary immersion
• Primary Applications: Nutrient-solution testing, source-water verification, reservoir monitoring, dissolved oxygen measurement, and water-treatment quality control
• Suitable Growing Systems: Hydroponics, coco-based fertigation, deep-water culture (DWC), nutrient film technique (NFT), and recirculating systems
• Commercial Applications: Cultivation facilities, fertigation stations, irrigation-water testing, and multi-zone water-quality monitoring
• Included Accessories: SX751 meter, four dedicated electrodes, calibration solutions, three replacement DO membrane caps, DO refill solution, and rigid carrying case
• Replacement Consumables: DO membrane caps, DO electrode refill solution, and replacement electrodes
• Meter Warranty: 3 years
• Electrode Warranty: 6 months
• Important Operating Requirement: Allow the DO500 polarographic electrode to polarize for approximately five minutes before taking measurements.
Key Advantage: The Apera SX751 combines eight water-quality measurement parameters in one portable instrument, reducing the need to carry separate meters for pH, ORP, dissolved oxygen, and conductivity. Its broad conductivity range accommodates both low-conductivity source water and concentrated nutrient solutions, while the fast-polarizing DO electrode supports efficient oxygen monitoring. Automatic electrode recognition, IP57 protection, and 400-record data storage make it particularly useful for commercial cultivation operations that need consistent water-quality checks across multiple reservoirs and irrigation zones.