This MLSS Sensor is an optical submersible probe designed for continuous online measurement of Mixed Liquor Suspended Solids (MLSS) concentration in activated sludge systems.

Adopting infrared scattering measurement principle, it accurately senses suspended biomass in mixed liquor and directly outputs MLSS value, with fast response and stable long-term performance. Built-in Pt1000 temperature sensor provides automatic temperature compensation, effectively correcting measurement drift caused by water temperature changes.

Standard RS485 Modbus RTU digital communication enables convenient connection with transmitters, PLC and industrial control systems. Optional self-cleaning wiper version reduces fouling on optical window and lowers maintenance frequency in high-sludge environment.

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

Widely used in activated sludge aeration tank, secondary settling tank, sludge concentration tank, wastewater treatment process control and sludge dewatering monitoring.

MLSS Sensor is an in-line optical probe for online monitoring of Mixed Liquor Suspended Solids (sludge concentration) in activated sludge systems. It adopts the infrared light scattering principle, directly measuring the concentration of suspended solids in mixed liquor without sampling or pre-treatment. Built-in temperature compensation and anti-fouling design ensure stable readings. With IP68 waterproof housing and RS485 Modbus-RTU digital output, it easily connects with transmitters, PLC and IoT platforms for automated wastewater treatment control.

Key Advantages

1.Infrared scattered light measurement, strong anti-interference against bubbles and water color
2.Real-time measurement of sludge concentration, no sampling or pre-treatment needed
3.IP68 fully sealed probe, suitable for long-term underwater immersion
4.Built-in temperature compensation, stable measurement in variable water temperature
5.Optional automatic cleaning brush, reduce manual maintenance frequency
6.Compact structure, easy installation and on-site calibration

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