Luminescent optical DO measurement with auto triple compensation and GLP datalogging — no membrane, no electrolyte, no hassle.
The Apera DO8500 (SKU: AI485) is a portable luminescent optical dissolved oxygen meter built for reliable, low-maintenance monitoring in commercial hydroponics, aquaculture, and nutrient-solution applications. Automatic compensation for salinity, temperature, and air pressure — combined with a 500-group GLP/GMP datalogger and USB output — makes it the most capable portable DO kit in Apera's lineup.
The Apera DO8500 measures dissolved oxygen in water using luminescence (fluorescence-quenching) technology rather than the traditional polarographic or galvanic electrochemical method. Where a polarographic probe continuously consumes oxygen and requires a minimum water flow rate to function, the optical probe in the DO8500 does not consume oxygen at all — which means it reads accurately in both static reservoirs and flowing recirculating systems without stirring or agitation.
The meter's DO803 luminescent optical probe ships with a 10-foot cable, a built-in temperature sensor for automatic temperature compensation, and a calibration/storage sleeve. The luminescent sensor cap (DO8032) carries a special light-blocking and chemical-resistant coating that prevents interference from ambient light or dissolved chemicals. Rated service life of the luminescent cap exceeds 8,000 hours. The meter body itself is IP67-rated — fully dustproof and waterproof — and includes a foldable stand so it can function as a bench unit when needed.
Commercial cannabis and hemp operations running deep water culture (DWC), recirculating drain-to-waste, NFT, or RDWC systems need accurate dissolved oxygen data to maintain root-zone health. DO is one of the parameters most directly tied to root rot incidence and pythium pressure — keeping nutrient solution between roughly 8–10 mg/L at reservoir temperature is a standard protocol for high-density cultivation. A meter that drifts, requires frequent membrane changes, or demands water agitation to read correctly is a liability in a production environment.
The DO8500 is also appropriate for irrigation-water testing ahead of fertigation events, post-harvest cleaning solution monitoring, and any application where a compliant data trail matters. The GLP/GMP datalogger stores 500 tagged readings with time and date stamps, and the USB port transfers data directly to a PC using Apera's included PC-Link software — supporting the documentation workflows required in licensed cannabis operations.
Triple automatic compensation — salinity, barometric pressure, and temperature — is handled simultaneously with no manual input required. The salinity probe included in the kit feeds real-time conductivity data to the meter so that salinity compensation is dynamic, not a fixed offset. This is critical in nutrient-solution environments where EC shifts across a fertigation cycle. Air pressure is factory-calibrated and can be manually adjusted if the operation is at significant elevation.
Calibration is one-point (air-saturation) using the included calibration sleeve, and takes one to two minutes. Unlike polarographic probes, frequent recalibration is not necessary — the optical sensor does not drift in the same way a membrane-based probe does. The meter supports display in mg/L, ppm, or % saturation, switchable with a single key press. Advanced digital processing provides both stable-reading and auto-lock display modes, and the backlit LCD shows DO reading and temperature simultaneously.
The AI485 kit ships as a complete test package: the DO8500 meter, the DO803 luminescent optical DO probe with 10-foot cable, a salinity probe (conductivity electrode), a calibration/storage sleeve, PC-Link software, a USB communication cable, and a rugged hard-shell carrying case. Three AA alkaline batteries power the meter; battery life exceeds 200 hours without backlight. Replacement sensor caps (DO8032) are available separately and are the only consumable in the system.
For cultivation operations, the 10-foot probe cable provides enough reach to test reservoir tanks or sumps without moving the meter. The IP67 body survives regular wash-down environments. For teams that need documented batch records — required under many state cannabis compliance frameworks — the 500-point timestamped datalogger with USB export replaces handwritten DO logs. Warranty coverage: 3 years on the DO8500 instrument, 2 years on the DO803 probe body, 1 year on the DO8032 sensor cap.
| Model | DO8500 |
| SKU | AI485 |
| DO Measurement Range | 0–20.00 mg/L (ppm); 0–200.0% saturation |
| Resolution | 0.01 / 0.1 mg/L (ppm); 0.1 / 1% saturation |
| Accuracy | ±2% reading or ±0.2 mg/L, whichever is greater |
| Response Time | ≤30 s (25°C, 90% response); stable reading in 1–3 minutes |
| Compensation | Auto: temperature, salinity (via included conductivity probe), barometric pressure |
| Datalogger | 500 groups, GLP/GMP format with time & date stamp; USB output |
| Probe Cable Length | 10 ft (DO803 optical DO probe) |
| Probe Cap Diameter | Approx. 1.3 in (3.3 cm) |
| Luminescent Cap Service Life | >8,000 hours |
| IP Rating | IP67 (meter body) |
Polarographic probes consume oxygen during measurement, which means they require constant water movement around the probe tip to read accurately. They also need periodic electrolyte refills and membrane replacements. The DO8500's optical (luminescent) probe does not consume oxygen, so it reads accurately in both static and flowing water with no membrane or electrolyte needed. This significantly reduces ongoing maintenance and eliminates the drift that membrane-based probes develop between changes.
Frequent calibration is not required. The optical sensor is inherently more stable than polarographic designs. When calibration is needed, the one-point air-saturation process using the included calibration sleeve takes one to two minutes — far faster than a two-point electrochemical calibration.
Yes. The kit includes a dedicated salinity (conductivity) probe that feeds real-time data to the meter for dynamic automatic salinity compensation. This is relevant in cannabis cultivation because nutrient solutions carry dissolved salts that affect DO solubility — a meter without salinity compensation will over-read DO in high-EC nutrient reservoirs.
The DO8032 is the luminescent sensor cap that screws onto the end of the DO803 probe — it contains the fluorescent coating that the optical measurement relies on. Rated service life exceeds 8,000 hours of use. It carries a 1-year warranty and is available as a standalone replacement. The probe body (DO803) itself carries a separate 2-year warranty.
The DO8500 stores up to 500 measurement groups, each tagged with a time and date stamp from the meter's real-time clock. Data transfers to a Windows PC via the included USB cable and Apera PC-Link software, where readings can be reviewed, exported, and archived. This is useful for generating the documentation trails required under licensed cannabis compliance programs.
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