The Apera PH850-PW (AI5541) is a professional handheld pH meter designed for reverse-osmosis (RO), distilled, deionized (DI), and other low-ionic-strength water sources. It features the Swiss-made LabSen 803 electrode with an ultra-low-resistance glass membrane and adjustable sleeve junction, helping produce stable readings in purified water where standard pH probes often drift. It delivers ±0.01 pH accuracy with typical stabilization in 30–60 seconds.
• Brand: Apera Instruments
• Model / SKU: PH850-PW / AI5541
• pH Range / Accuracy: 0–14 pH / ±0.01 pH
• Included Electrode: Swiss LabSen 803 3-in-1 glass pH/temperature electrode
• Electrode Membrane: L-type cylindrical glass, resistance below 50 MΩ
• Junction Design: Adjustable movable sleeve junction for controlling electrolyte flow
• Stabilization Time: Approximately 30–60 seconds in RO/DI water
• Calibration: Automatic 1–3-point calibration; recognizes five standard buffers
• Temperature Range: 0–80°C (32–176°F)
• Protection Rating: IP57 waterproof and dustproof
• Power Supply: 3 × AA batteries
• Connectivity: BNC pH and RCA temperature connectors; compatible with optional ORP electrode
• Warranty: 3 years for the meter; 6 months for the electrode
Key Advantage: The PH850-PW is specifically engineered for purified and low-ion water, offering more stable readings than conventional pH electrodes. Its adjustable junction, rapid stabilization, and replaceable electrode make it particularly useful for RO/DI water quality verification before nutrient preparation.