The Apera SX725 (AI465) is a dual-parameter handheld meter designed for laboratory-grade pH and dissolved oxygen (DO) measurement in commercial cultivation, hydroponics, and water-management applications. It allows operators to verify nutrient-solution acidity and oxygen levels directly at reservoirs, irrigation systems, and other sampling points without transporting samples to a laboratory. The complete kit includes a 201T-S combination pH/temperature electrode and Apera's proprietary 3-in-1 polarographic dissolved oxygen electrode. The DO probe features a shortened polarization time of approximately five minutes and reaches 90% of its final reading within 30 seconds of immersion. Automatic electrode recognition switches the measurement mode according to the connected probe, while automatic temperature and salinity compensation helps maintain reliable DO readings. The IP57-rated meter stores up to 300 measurement records, allowing operators to review readings across multiple reservoirs and cultivation zones.
• Product Type: Handheld pH and dissolved oxygen meter kit
• Brand: Apera Instruments
• Model: SX725
• SKU: AI465
• Measurement Parameters: pH, dissolved oxygen (DO), and temperature
• DO Measurement Range: 0–20.00 mg/L
• pH Accuracy: ±0.01 pH
• DO Electrode Type: Proprietary 3-in-1 polarographic electrode
• pH Electrode: 201T-S combination pH/temperature electrode
• pH Electrode Construction: Lithium-glass membrane and ceramic diaphragm
• DO Electrode Cable Length: 2 meters
• DO Polarization Time: Approximately 5 minutes before measurement
• DO Response Time: Reaches 90% of its final reading within approximately 30 seconds of immersion
• pH Calibration: Automatic 1-, 2-, or 3-point calibration
• Recognized pH Buffers: 1.68, 4.00, 7.00, 9.18, and 12.45
• Included Calibration Solutions: Bottled pH 4.00, 7.00, and 10.00 buffers
• DO Calibration: One-point calibration using an air-saturated calibration sleeve
• Temperature Compensation: Automatic for pH and DO measurements
• Salinity Compensation: Automatic during DO measurement
• Barometric Pressure Compensation: Manual adjustment for altitude-related pressure differences
• Electrode Recognition: Automatically switches measurement mode according to the connected electrode
• Digital Filtering: Reduces signal noise to improve reading stability
• Electrode Diagnostics: Self-diagnosis helps identify electrode-condition and calibration issues
• Data Storage: Up to 300 measurement records
• Data Recall: Stored readings can be reviewed directly on the meter
• Water and Dust Protection: IP57-rated meter body, designed to withstand dust exposure and temporary immersion
• Primary Applications: Water-quality testing, nutrient-reservoir monitoring, and dissolved oxygen verification
• Suitable Growing Systems: Hydroponics, deep-water culture (DWC), nutrient film technique (NFT), and recirculating deep-water culture (RDWC)
• Included Components: SX725 meter, 201T-S pH/temperature electrode, polarographic DO electrode, pH calibration solutions, 3M KCl electrode-storage bottle, calibration sleeve, supporting accessories, and rugged hard-sided carrying case
• Warranty: Confirm the current meter and electrode warranty with the supplier.
Key Advantage: The Apera SX725 combines pH and dissolved oxygen measurement in one portable instrument, allowing operators to verify both nutrient acidity and oxygen availability across multiple reservoirs. Its five-minute DO polarization period, fast response, IP57 protection, and 300-record data logger make it practical for routine monitoring in demanding cultivation environments. Automatic temperature and salinity compensation further support reliable DO measurements, while the rugged carrying case keeps the meter and its accessories together for field use.