Lab-grade 7-parameter water quality measurement in a single IP57-rated field kit.
The Apera SX736 (AI468) measures pH, dissolved oxygen, conductivity (EC), TDS, salinity, resistivity, and temperature from one handheld unit — with automatic electrode recognition, on-board data logging, and a rugged IP57-rated housing built for daily grow-room use.
The Apera SX736 is a portable, lab-grade multiparameter meter capable of measuring seven water quality parameters in the field: pH, mV, dissolved oxygen (DO), conductivity (EC), TDS, salinity, resistivity, and temperature. It ships as a complete kit with three dedicated electrodes — the 201T-S pH/temp electrode, the 2301T-S BPB conductivity/temp electrode, and the polarographic DO500 electrode — plus calibration solutions, 3M KCl storage solution, three replacement DO membrane caps, refill solution, and a hard-shell carrying case.
Where single-parameter meters require you to pull three separate instruments for a full water quality check, the SX736 consolidates that workflow into one unit. Automatic electrode recognition switches the meter to the correct parameter mode when you swap probes — no manual mode-selection required.
Licensed cannabis and hemp operations running recirculating hydroponic systems, coco/perlite fertigation lines, or DWC reservoirs need reliable, repeatable water data. pH drift kills uptake efficiency. Unchecked EC swings stress plants at critical production phases. DO deficits in reservoir water are a direct driver of root zone anaerobic conditions and pathogen pressure.
The SX736 handles all three primary checks — pH, EC, and DO — in a single calibration session, from a single kit. For multi-site operators or cultivation directors auditing reservoir health across rooms or facilities, the 400-data-set on-board memory means readings can be logged at point-of-measurement and reviewed or exported afterward rather than hand-recorded. The IP57 rating means the unit tolerates the spray, humidity, and nutrient-solution exposure of an active grow room without damage.
Electrode technology on the SX736 is a meaningful differentiator from entry-level field meters. The 201T-S pH electrode uses a lithium glass membrane and single ceramic junction, rated for slope ≥97% when new and with a 0–80°C (32–176°F) temperature range. The 2301T-S conductivity electrode is built on Apera's Brush-resistant Platinum Black (BPB) technology, covering a continuous 0–200 mS/cm range on a single 1-point calibration. The DO500 polarographic electrode provides automatic temperature and salinity compensation and reaches 90% DO response within 30 seconds of submersion, with full electrode polarization in only 5 minutes.
Digital filter technology is integrated into the meter's microprocessor to improve response speed and reduce noise in readings. A stability indicator (smiley face icon) confirms the reading has settled before you log it. Pure-water modes are available for both pH and conductivity to increase accuracy in low-ionic-strength solutions — relevant for RO or DI source water applications. Calibration is 1–3 point for pH and 1-point for EC, with auto temperature compensation active across both.
The SX736 meter body is rated IP57 — dust-tight and capable of withstanding immersion up to 1 meter for 30 minutes. At 180 g and 65 × 120 × 31 mm, it fits in a coat pocket or tool bag. The complete kit ships in a rigid carrying case that organizes the meter, all three electrodes, and consumables in one package ready for fieldwork.
Apera backs the instrument with a 3-year manufacturer's warranty against defects in materials and workmanship. Probes and electrodes carry a 6-month warranty — standard for consumable electrodes in this class. Replacement membrane caps and refill solution for the DO electrode are included in the kit, extending service intervals before a separate consumable purchase is needed.
| SKU | AI468 |
| Model | Apera SX736 |
| Parameters Measured | pH, mV, Dissolved Oxygen (DO), Conductivity (EC), TDS, Salinity, Resistivity, Temperature |
| pH Range | -2.00 to 19.99 pH |
| pH Accuracy | ±0.01 pH |
| pH Resolution | 0.1 / 0.01 pH |
| pH Calibration | 1–3 point, automatic |
| Conductivity Range | 0.00 μS/cm – 200 mS/cm (auto-ranging) |
| Conductivity Electrode | 2301T-S BPB (Brush-resistant Platinum Black), 0–200 mS/cm, 1-point calibration |
| DO Electrode | DO500 polarographic; auto temp & salinity compensation; 90% response in 30 sec; polarization in 5 min |
| pH Electrode | 201T-S, lithium glass membrane, single ceramic junction, slope ≥97%, 1 m cable |
| Temperature Compensation | Automatic (ATC) for pH and conductivity; 0–100°C (pH ATC range) |
Yes — each electrode type has its own calibration routine. The SX736 supports 1–3 point pH calibration and 1-point EC calibration. The meter's automatic electrode recognition detects which probe is connected and steps you into the correct calibration mode automatically. DO electrode polarization takes 5 minutes before the first measurement session.
Yes. The 2301T-S BPB conductivity electrode covers a continuous range of 0 to 200 mS/cm on a single 1-point calibration. Commercial cannabis fertigation solutions typically run 2–6 mS/cm EC — well within range. The meter also converts conductivity readings to TDS and salinity automatically, so you can read in whichever unit your nutrient program specifies.
Low DO in reservoir or irrigation water directly limits root-zone aerobic activity and creates conditions favorable to Pythium and other anaerobic pathogens. Monitoring DO at the reservoir and at point-of-delivery lets you confirm aeration equipment is working and catch problems before they reach the root zone. The SX736's polarographic DO electrode automatically compensates for temperature and salinity, both of which affect oxygen solubility.
IP57 means the meter is fully dust-tight (6 = total dust exclusion is actually IP6x; IP57 is dust-protected and submersion-rated to 1 m for 30 minutes). It is designed to withstand splashing, spray, nutrient-solution contact, and high-humidity environments. It is not rated for continuous submersion. The electrodes have their own 1-meter cables, keeping the meter body away from the solution during measurement.
The SX736 kit includes the meter, all three electrodes (201T-S pH, 2301T-S conductivity, DO500 DO), 3 replacement DO membrane caps, DO refill solution, 3M KCl electrode storage solution, calibration solutions, and a hard-shell carrying case. Replacement membrane caps and electrode storage solution are the primary consumables to track. Electrodes themselves carry a 6-month warranty and will eventually need replacement with regular daily use.
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