NBL-WQ-MLSS-4S Online Sludge Concentration Sensor | Industrial Water Quality Monitoring for Sewage Treatment

NiuBoL NBL-WQ-MLSS-4S online sludge concentration sensor adopts 90° infrared scattered light technology, specially designed for MLSS monitoring in sewage treatment processes. It features IP68 high-level protection and 316L stainless steel shell, supports RS485 Modbus RTU protocol, and provides high-precision, high-stability industrial-grade water quality monitoring solutions.

Deeply Optimize Process Efficiency: NiuBoL Industrial-grade Online Sludge Concentration (MLSS) Sensor

Overcoming high turbidity measurement drift pain points, providing long-term stable digital monitoring for environmental engineering.

• Infrared Scattered Light Measurement Technology: Unaffected by ambient light interference, ensuring accurate and linear readings even in high-concentration sludge environments.

• 316L Stainless Steel and ABS Dual-effect Shell: Optimized for complex biochemical tank conditions, balancing corrosion resistance and mechanical strength.

• Extremely Simple System Integration: Full digital signal output, supports standard protocols, greatly shortening the development cycle for integrators.

NBL-WQ-MLSS-4S Online Sludge Concentration Sensor Product Overview

In the biochemical processes of sewage treatment (such as A2O, SBR, MBR), real-time monitoring of mixed liquor suspended solids concentration (MLSS) is the key to maintaining microbial activity and optimizing return ratios. Traditional manual sampling analysis has strong hysteresis and cannot achieve closed-loop control.

NiuBoL NBL-WQ-MLSS-4S integrated online sludge concentration sensor is born to solve this industrial pain point. It perfectly integrates fiber optic structure with industrial-grade signal converter, capable of capturing scattered light signals generated by suspended particles in water samples in real time and converting them into standard digital data.

NBL-WQ-MLSS-4S Online Sludge Concentration Sensor Core Technical Advantages

1. Backscattered Light and Fiber Optic Structure

The sensor uses a high-stability infrared LED as the light source. The beam enters the water body through a precise fiber optic path. Utilizing the scattering effect of suspended particles on light, it measures the intensity of backscattered light and combines it with NiuBoL's proprietary linearization compensation algorithm to achieve ultra-wide range coverage of 0～20.000 g/L. The fiber optic structure design not only reduces the sensor volume but also significantly enhances its anti-interference ability against natural light and external stray light.

2. Material Reliability under Harsh Working Conditions

Considering possible chemical corrosion and physical impact in biochemical tanks and aeration tanks, the NBL-WQ-MLSS-4S shell uses 316L stainless steel and ABS engineering plastic. This material combination can effectively resist corrosion from domestic sewage and some industrial wastewater. Combined with IP68 deep sealing design, the sensor can serve online for a long time in environments within 20 meters water depth, reducing operation and maintenance costs caused by equipment damage.

3. Precise Automatic Temperature Compensation (Pt1000)

The accuracy of sludge concentration measurement is often affected by environmental temperature fluctuations. NiuBoL integrates a high-sensitivity Pt1000 temperature sensor inside the sensor. Real-time temperature compensation performed by the microprocessor eliminates measurement errors caused by seasonal changes or process temperature rises, ensuring data always maintains ±5% industrial accuracy standard within 0～50℃.

4. Open Digital Communication, Adapting to IIoT Architecture

To meet the challenges of Industry 4.0 and smart water affairs, the sensor comes standard with RS-485 interface and strictly follows the Modbus/RTU protocol. Integrators can directly connect the sensor to PLC, remote terminal unit (RTU) or cloud gateway without expensive secondary transmitters. At the same time, it retains 4-20mA analog output function, ensuring perfect downward compatibility with traditional control systems.

NBL-WQ-MLSS-4S Online Sludge Concentration Sensor Technical Specifications

Typical Application Scenarios

• Sewage treatment biochemical tanks: Monitor MLSS concentration in aeration tanks and return sludge pipelines to achieve automatic return control and energy-saving aeration.

• Drain outlet monitoring: Real-time monitoring of suspended solids content in discharged water to ensure compliant discharge at the end of the process and avoid environmental risks.

• Tap water plant raw water treatment: Monitor the concentration of the grit chamber of incoming raw water to optimize the dosing ratio of flocculants.

• Industrial process control: Applied to industrial liquid monitoring such as mining washing, papermaking fiber recovery, etc., to grasp slurry concentration changes in real time.

Installation Instructions and Electrical Connection Guide

Physical Installation Recommendations

1. Wall Distance: During installation, the sensor should be vertically downward, with the measuring surface at least 5cm from the side wall and at least 10cm from the pool bottom to avoid high readings caused by wall reflection.

2. Bubble Avoidance: When used in aeration tanks, try to avoid directly above dense bubble areas, or use baffles for flow guidance to prevent bubbles from interfering with the optical window.

Electrical Wiring Definition

The sensor uses a 5-core shielded cable. To ensure equipment safety, please carefully check the following definitions before wiring:

• Red wire: Power positive (12～24V DC)

• Black wire: Power ground (GND)

• Blue wire: RS-485 A

• Green wire: RS-485 B

• Yellow wire: 4-20mA current output (if only digital communication is used, please insulate and leave this wire floating)

Safety Tip: All cable connections must be professionally waterproof sealed. If the cable is exposed to strong light or corrosive gas, it is recommended to use protective sleeving. The cable should hang naturally and must not be overstretched.

FAQ

Q1. Does the NiuBoL sludge concentration sensor require frequent calibration?

A: No. Due to the use of infrared scattering method and high-stability light source, it is recommended to perform a calibration check every 3-6 months under stable working conditions.

Q2. Why does the sensor not read zero in clean water?

A: This may be caused by a dirty window or the installation position being too close to the pool bottom. Please clean the window first and perform zero point calibration.

Q3. Can this sensor be used to measure industrial wastewater containing seawater?

A: Yes. The shell is made of 316L stainless steel, which has good salt spray and corrosion resistance, but attention should be paid to regularly cleaning marine organisms from the optical window.

Q4. Will there be conflict if 4-20mA signal and RS-485 are connected at the same time?

A: No. NBL-WQ-MLSS-4S supports dual signal output, convenient for local display instruments and remote cloud platforms to obtain data simultaneously.

Q5. What causes the data to suddenly jump significantly during operation?

A: Please check whether large suspended objects (such as rags, plastic bags) are wrapped around the sensor, or whether a large number of bubbles are attached to the measurement window.

Q6. What does the measurement resolution of 0.001g/L mean?

A: This means the sensor can detect sludge concentration changes as small as 1mg/L, providing excellent sensitivity for low concentration conditions.

Q7. Can the sensor cable be extended by myself?

A: Yes, but it is recommended to use shielded twisted pair for extension. The total length after extension should not exceed 1000 meters (for RS-485), and the power supply voltage must be stable.

Q8. Does the sensor support online self-cleaning function?

A: This model (4S) focuses on integrated design and recommends regular manual wiping. If automatic brush cleaning function is needed, please consult our sales engineers for NiuBoL high-end series solutions with self-cleaning function.

NiuBoL NBL-WQ-MLSS-4S sludge concentration sensor has become a "star product" in the field of environmental engineering integration with its sturdy and durable 316L body, anti-interference fiber optic technology and standardized Modbus digital interface. In today’s era that emphasizes precise dosing, energy saving and emission reduction, having a stable and reliable monitoring sensor is the ultimate guarantee of project delivery quality.

Are you looking for a water quality sensor that can significantly reduce operation and maintenance complaints and improve project automation level?

NBL-WQ-MLSS-4A Online Sludge Concentration Sensor Data Sheet

NBL-WQ-MLSS-4A Online Sludge Concentration Sensor.pdf