RS485 Fluorescence Dissolved Oxygen Sensor (Freshwater)

The RS485 Fluorescence Dissolved Oxygen Sensor is an industrial-grade optical water quality probe tailored for continuous freshwater monitoring. Using fluorescence quenching and built-in temperature compensation, it delivers accurate dissolved oxygen and saturation data without consuming oxygen or requiring electrolyte maintenance. It is well suited to makers, educators, and engineers managing aquaculture tanks, hydroponic systems, and environmental monitoring stations.

Maintenance-free optical sensing

The probe measures dissolved oxygen via optical fluorescence quenching, avoiding electrode polarisation and electrolyte depletion. It captures dissolved oxygen from 0 to 20 mg/L (0 to 200% saturation) at a resolution of 0.01 mg/L with an error margin of plus or minus 3% FS.

Automatic real-time temperature compensation

A dedicated built-in temperature sensor monitors fluid conditions between 0 and 40 degrees Celsius to apply automatic compensation to every dissolved oxygen reading. This maintains measurement accuracy across fluctuating water temperatures.

Industrial RS485 ModBus communication

Designed for long-distance data transmission, the sensor interfaces via standard ModBus-RTU over RS485 and runs on DC 10 to 30V power at 0.2W. It arrives factory calibrated and supports user-configured zero and full-scale calibration via internal registers.

Submersible IP68 protective build

Built for harsh continuous immersion, the probe features a 316 stainless steel front, corrosion-resistant plastic casing, and pressure resistance up to 0.6 MPa. It includes a 5-metre connection cable and a fluorescent sensing film rated for one year of standard use.

Freshwater monitoring and control

The sensor is suited for monitoring fish pond aeration, controlling biological wastewater treatment processes, and tracking hydroponic nutrient solutions. It also supports remote logging in freshwater streams, dams, and reservoirs.

Downloads & documentation

• Product wiki (DFRobot)