This Sludge Density Meter RS485 is a wall-mounted industrial analyzer, matched with optical sludge sensor for continuous online measurement of sludge concentration and Mixed Liquor Suspended Solids (MLSS) in wastewater treatment.

It supports dual signal output of standard 4-20mA analog and RS485 Modbus RTU digital communication, convenient for connecting PLC, DCS and remote cloud monitoring systems. Built-in automatic temperature compensation algorithm corrects measurement deviation caused by water temperature changes, improving data stability and accuracy.

Equipped with large LCD display, one-key calibration, high/low limit relay alarm and automatic control function, realizing intelligent on-site sludge process management. The front panel reaches IP65 protection grade, dust-proof and splash-proof, suitable for humid and harsh environment in wastewater plants.

Widely used in activated sludge aeration tank, secondary settling tank, sludge thickening tank, sludge dewatering system and industrial wastewater process control.

Sludge Density Meter RS485 is an online instrument for continuous measurement of sludge concentration in wastewater treatment. It matches with an infrared optical sludge density sensor to measure the concentration of activated sludge in real time. Equipped with a digital signal module, it supports high/low limit alarm and relay output for automatic sludge discharge and dosing control. The isolated 4-20mA analog output plus RS485 Modbus-RTU digital communication allows easy connection to PLC, DCS and IoT platforms for automated water treatment management.

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