Lab-grade 8-parameter field testing — pH, ORP, DO, EC, TDS, salinity, resistivity & temp in one rugged kit.
The Apera SX751 (AI469) is a handheld 8-in-1 multiparameter meter kit built for lab-quality measurement of pH, ORP (redox), dissolved oxygen, conductivity, TDS, salinity, resistivity, and temperature in the field. IP57-rated and shipping as a complete kit with four dedicated electrodes and a rugged carrying case, it's designed for operators who need traceable, multi-analyte water data away from a fixed bench.
The Apera SX751 is a portable, handheld multiparameter meter engineered for laboratory-quality measurement of up to eight water quality parameters directly in the field: pH, ORP (oxidation-reduction potential), dissolved oxygen (DO), electrical conductivity (EC), total dissolved solids (TDS), salinity, resistivity, and temperature. It ships as the AI469 complete kit, which includes four dedicated electrodes — the 201T-S pH/temperature combination electrode, the 301Pt-S ORP electrode with a proprietary platinum ring sensor, the 2301T-S conductivity/temperature electrode (cell constant K=1.0), and the DO500 polarographic dissolved oxygen electrode — along with calibration solutions, replacement DO membrane caps, and a rigid carrying case.
The meter's automatic electrode recognition means it switches to the correct parameter mode as soon as the corresponding probe is connected, eliminating manual mode-selection errors in a busy grow environment. All four electrodes include built-in temperature sensors that feed the meter's automatic temperature compensation, keeping readings accurate across the full operating range regardless of ambient fluctuations.
Commercial cannabis and hemp cultivation operations running recirculating hydroponic systems, coco-based fertigation, or reservoir-fed flood-and-drain need to track multiple water quality parameters simultaneously — and a single-parameter pen tester simply doesn't cut it at scale. The SX751 is the right tool for head growers and cultivation managers who need to verify nutrient solution pH and EC together, confirm dissolved oxygen levels in reservoir water, monitor ORP as a proxy for sanitation efficacy, and log all of that data in one instrument rather than juggling three or four separate testers.
It's equally suited for compliance and QA use cases: state-licensed operators capturing irrigation water quality records, testing source water before it enters an RO system, or verifying that fertigation targets are being hit consistently across multiple zones or facilities. The 400-point onboard data log with recall gives you an audit trail without requiring an immediate PC connection after every measurement.
Apera's proprietary digital filter technology improves both response time and measurement accuracy across all parameters. For dissolved oxygen specifically, the DO500 polarographic electrode polarizes in just 5 minutes — compared to an industry average of roughly 30 minutes — and achieves a 90% response within 30 seconds of immersion. The 2301T-S conductivity electrode uses a platinum black sensor to maintain accurate readings across a conductivity range of 0 to 200 mS/cm (0 to 200,000 µS/cm), which covers nutrient solution concentrations from RO water through high-EC aggressive-feed programs. The 301Pt-S ORP electrode uses a platinum ring sensor for fast, stable redox readings in general water solutions.
The meter runs a full suite of intelligent automation: auto-calibration (1–3 point for pH, 1-point for EC), automatic temperature compensation on all relevant parameters, self-diagnosis, data logging with 400-set storage and recall, and auto power-off to preserve battery life in field conditions. The IP57-rated housing protects against dust ingress and temporary immersion, making it viable in wet environments like fertigation rooms and reservoir bays.
For a large-scale cultivation operation, water quality data is yield-critical data. pH drift outside the target window locks out nutrient uptake regardless of how precisely a fertigation recipe is dialed in. EC that runs high under heat stress can trigger tip burn or osmotic stress before visible symptoms appear. Dissolved oxygen in reservoir water directly affects root zone health in DWC and NFT systems. The SX751 puts all of that into one calibrated, IP57-rated instrument that can move from the source water tank to the drain-return line to the reservoir without switching tools.
Electrode replacements and consumables for the SX751 are stocked separately, and the DO membrane cap kit ships in the box with three replacements plus refill solution, so the instrument is ready for extended use straight out of the case. The three-year instrument warranty and six-month electrode warranty from Apera Instruments provide a clear maintenance window for operations budgeting equipment lifecycle costs. HSC carries the SX751 AI469 kit with direct account pricing — contact us to request a quote.
| SKU | AI469 |
| Model | Apera SX751 |
| Parameters | pH, ORP, DO, EC, TDS, Salinity, Resistivity, Temperature |
| IP Rating | IP57 (dust-tight, temporary immersion) |
| Conductivity Range | 0 – 200 mS/cm (0 – 200,000 µS/cm) |
| DO Range | 0 – 20.00 mg/L |
| DO Electrode Polarization | 5 minutes (vs. ~30 min industry average) |
| DO Response Time | 90% response within 30 seconds |
| Data Log Capacity | 400 data sets (store and recall) |
| pH Calibration | 1–3 point auto-calibration |
| EC Calibration | 1-point auto-calibration |
| Included Electrodes | 201T-S pH/Temp, 301Pt-S ORP, 2301T-S Conductivity/Temp (K=1.0), DO500 Polarographic DO |
Yes. The 2301T-S conductivity electrode measures from 0 to 200 mS/cm (0 to 200,000 µS/cm), which covers the full range from RO source water through aggressive high-EC nutrient programs and well beyond. It uses a platinum black sensor with built-in temperature compensation for accuracy across that entire range.
The DO500 polarographic electrode polarizes in approximately 5 minutes. Apera lists the industry average at around 30 minutes, so in a busy production environment this is a meaningful time savings. Once polarized, the electrode reaches a 90% response within 30 seconds of immersion.
Yes. The meter has an onboard data log that stores and recalls up to 400 data sets. For licensed operators maintaining water quality records, this allows multiple readings across a session to be captured and retrieved without needing a laptop connected during testing.
No. The SX751 features automatic electrode recognition — the meter detects which probe is connected and switches to the corresponding measurement mode automatically. This reduces user error when moving quickly between parameters in a multi-zone testing routine.
The complete kit ships with four electrodes: the 201T-S pH/temperature combination electrode, the 301Pt-S ORP electrode (platinum ring sensor), the 2301T-S conductivity/temperature electrode (K=1.0, platinum black sensor), and the DO500 polarographic dissolved oxygen electrode. Three replacement DO membrane caps and matching refill solution are also included, along with calibration solutions and a rigid carrying case.
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