Activated Sludge Sensor is an in-line optical probe specially designed for monitoring activated sludge concentration in biological wastewater treatment. It adopts the infrared light scattering principle to measure the suspended solids in mixed liquor in real time. Built-in temperature compensation and anti-fouling design ensure long-term stable performance. With IP68 waterproof housing and RS485 Modbus-RTU digital output, it connects with transmitters, PLC and IoT platforms for automated sludge process control.

Digital Activated Sludge Sensor RS485001

Activated Sludge Sensor is an optical submersible probe specially designed for continuous online monitoring of activated sludge concentration and biomass in biological wastewater treatment systems.

Adopting infrared scattering measurement principle, it accurately detects suspended activated sludge flocs in the mixed liquor and directly outputs sludge concentration value, with fast response and stable long-term performance. Built-in Pt1000 temperature sensor enables automatic temperature compensation, effectively reducing measurement error caused by water temperature fluctuation.

Standard RS485 Modbus RTU digital output allows convenient connection with transmitters, PLC and industrial control systems. Optional self-cleaning wiper version prevents sludge adhesion on optical window, significantly lowering maintenance frequency.

The sensor body adopts IP68 fully sealed anti-corrosion structure, supporting long-term submerged installation in aeration tank, secondary settling tank and sludge tank.

Widely used in activated sludge aeration tank, secondary settling tank, sludge return process, biological nitrogen removal tank and wastewater treatment process control.

Key Advantages

1.Digital RS485 communication, strong anti-interference for long-distance transmission
2.Matched with infrared optical probe, immune to bubbles and water color interference
3.Real-time sludge density display, intuitive for on-site operators
4.Relay output to realize automatic sludge discharge and dosing linkage
5.Dual signal output, compatible with various industrial control systems
6.User-friendly menu calibration, simple operation and maintenance

Sensor Technical Parameters

Function	Universal Secondary Instrument
Measurement Range	Depends on the sensor
Measurement Resolution	0.1, 0.01
Measurement Accuracy	±5% F.S.
Temperature Compensation	Reads sensor data
Temperature Range	0.0 to +50.0°C
Temperature Resolution	0.1°C
Temperature Accuracy	±0.2°C
Operating Temperature	0 to +70°C
Storage Temperature	-20 to +70°C
Display	Large backlit dot-matrix LCD
Current Output (Measured)	Isolated 4–20mA, max load 500Ω
Current Output (Temperature)	Isolated 4–20mA, max load 500Ω
Current Output Accuracy	±0.05mA
RS485	Modbus RTU standard protocol
Communication Rate	9600/19200/38400/115200
Relay Contact Capacity	5A/250VAC, 5A/30VDC
Timer Control Relay (Optional)	Cleaning
Relay Delay Action	0–120 seconds
Protection Level	IP65
Power Supply	90–260VAC, power <5W
Mounting Method	Panel mounting
Weight	144 series: 0.85 kg pH, mg/L, NTU, μS/cm, mS/cm, ppm, ppb, cells, null, mm/a, etc.

Sensor Technical Parameters

Parameter	Range
Measurement Range	0–10,000 mg/L, 0–20,000 mg/L, 0–30,000 mg/L, 0–50,000 mg/L (value × 0.001 = g/L)
Temperature Range	0.0–80.0°C (optional temperature compensation)
Housing Material	Stainless steel
Mounting Method	Threaded fixation
Signal Cable Length	5 m (customizable)
Accuracy	±5.0% F.S.
Power Supply	12V
Protection Level	IP68
Pressure Resistance	0–4 bar
Output	4–20mA (max load 750Ω), RS485/MODBUS-RTU

Application Fields

Municipal wastewater treatment: aeration tank, secondary sedimentation tank, sludge thickener
Industrial wastewater activated sludge process
Sludge dewatering and concentration monitoring
River, lake and reservoir water quality monitoring
Aquaculture water treatment