AL4190S In-Situ Low Turbidity Sensor: Online Turbidity Monitoring Solution for Water Supply and Industrial Water Treatment

In water supply treatment, industrial circulating water systems, and seawater utilization projects, low-concentration turbidity is an important control indicator to ensure factory water quality, pipe network safety, and stable process operation. System integrators and engineering contractors require high-sensitivity, low-drift, and easy-to-integrate online turbidity sensors to achieve continuous and reliable data acquisition. The Nexisense AL4190S in-situ low turbidity sensor and AL4190 low-range turbidity analyzer, based on the standardized 90° scattered light method, provide targeted measurement solutions for different working conditions.

AL4190S emphasizes in-situ submerged deployment with a compact and pressure-resistant structure; AL4190 optimizes laboratory-level measurement stability through a sample chamber and defoaming structure. Both support the RS485 Modbus protocol and can be directly connected to existing water treatment automation systems or IoT platforms, lowering the integration threshold.

AL4190S In-Situ Low Turbidity Sensor Core Technology

AL4190S adopts the 90° scattered light measurement principle that complies with ISO 7027/EN 27027 standards, with a detection lower limit of 0.05 NTU and a resolution of 0.001 NTU, meeting the high-precision requirements of low-turbidity water bodies. Pulse light modulation technology effectively reduces background noise and suppresses baseline drift, while narrow-band filters filter the receiving optical path, significantly eliminating stray light effects and ensuring that the measurement is not significantly affected by suspended particle diameter or water sample chromaticity.

The sensor housing is made of POM material, with IP66 protection rating and a maximum working pressure of 5 Bar, suitable for long-term submerged deployment. The 3 kV withstand voltage isolation power supply enhances anti-interference capability, and the interface is equipped with misconnection and reverse connection protection to improve on-site installation safety. The light source has a service life of more than 5 years. Combined with factory pre-calibration and fault self-diagnosis functions, it reduces maintenance frequency and data anomaly risks.

The response time is ≤10 seconds, power consumption is only 0.5 W, and the wide voltage input of 7-30 VDC makes it easy to adapt to various field power supply systems. The compact size (42 mm diameter × 165 mm length) facilitates flexible installation in pipelines, clear water tanks, or river channels, providing convenience for system integrators in space-constrained projects.

AL4190 Low-Range Turbidity Analyzer Design Advantages

AL4190 is optimized for scenarios with higher requirements for measurement stability, such as water supply plant effluent water, pipe network endpoints, and rural drinking water. The detection lower limit is as low as 0.03 NTU, the range covers 0-10 NTU and 0-40 NTU, repeatability is 0.5%, and accuracy is ±3% of the reading or 0.3 NTU. The built-in defoaming structure eliminates bubble interference during sampling, and the light chamber design further suppresses stray light, ensuring that the results are not significantly affected by chromaticity or dissolved organic matter.

The pluggable light source design facilitates on-site maintenance and replacement, with a response time of ≤30 seconds (including sampling time). The PP material housing and IP66 protection rating are suitable for indoor or semi-outdoor installation environments. It is also equipped with a 3 kV withstand voltage isolation power supply and Modbus protocol, supporting seamless docking with PLC or edge gateways.

Both products come with the free WQS-SUITE analysis software. Engineers can complete parameter setting, on-site calibration, real-time measurement verification, and fault diagnosis through the software, accelerating the debugging and operation and maintenance process.

Application Scenarios and System Integration Value

AL4190S in-situ sensor is suitable for filtered water monitoring in water supply treatment, industrial circulating cooling water systems, and seawater desalination pretreatment. Its submerged installation method requires no additional sampling pipelines, reducing maintenance points and clogging risks, and is particularly suitable for distributed monitoring in large water tanks or open water bodies.

The AL4190 low-range turbidity analyzer is more suitable for water supply plant effluent quality control, pipe network endpoint inspection points, and rural safe drinking water projects. In these scenarios, low turbidity data is directly related to disinfection efficiency evaluation and user-end water quality compliance. The sample chamber design and defoaming structure ensure high repeatability of measurement results, providing a reliable basis for process optimization and alarm threshold setting.

For system integrators, the standard RS485 Modbus-RTU protocol is the core advantage. The sensor can be mounted as a slave device on the same bus and synchronously collect parameters such as pH, residual chlorine, and dissolved oxygen to realize multi-parameter water quality monitoring nodes. Data can be directly uploaded to SCADA systems or IoT cloud platforms, supporting remote trend analysis and alarm linkage.

In project implementation, integrators can flexibly select models according to site conditions: prioritize AL4190S when space is tight or submerged installation is required; select AL4190 when extremely low turbidity stability is highly demanded. Both products support factory pre-calibration recovery, reducing on-site calibration difficulty and shortening the project debugging cycle.

Technical Parameter Specifications

AL4190S In-Situ Low Turbidity Sensor Parameters

AL4190 Low-Range Turbidity Analyzer Parameters

Both sensors support built-in fault self-diagnosis and factory pre-calibration recovery functions.

Deployment, Maintenance and Engineering Reliability

When installing AL4190S in situ, it is recommended to fix it vertically or horizontally in a representative water flow area to avoid dead water zones or direct strong light. The pressure-resistant design supports submerged deployment at a certain depth and is suitable for clear water tank or river channel monitoring. AL4190 requires a sampling pipeline, and the defoaming structure in front of the inlet can significantly reduce bubble interference.

In terms of maintenance, pulse light modulation and narrow-band filter design reduce the impact of optical component contamination on measurement. The light source has a service life of more than 5 years, and the pluggable design (AL4190) further facilitates replacement. Engineers can perform zero and span calibration regularly through the WQS-SUITE software. The software supports calibration curve storage for easy tracking of performance changes.

The 3 kV withstand voltage isolation power supply and interface protection circuit improve the stability of the sensor in electrical noise environments. The low power consumption feature makes it easy to integrate into low-power edge nodes or solar-powered systems, suitable for remote water supply pump rooms or rural drinking water monitoring points.

FAQ

Q1. How to choose between AL4190S and AL4190 in application scenarios?

AL4190S in-situ structure is suitable for direct submerged installation occasions, such as large water tanks, circulating water systems, or seawater monitoring, with simple installation and no need for sampling pipelines. AL4190 is equipped with a sample chamber and defoaming structure, making it more suitable for water supply plant effluent water or pipe network endpoint monitoring that requires extremely high measurement repeatability. Integrators can select the model according to whether sampling is needed, space conditions, and turbidity lower limit requirements.

Q2. How to integrate the AL4190 series sensors into existing PLC or SCADA systems?

Both products use the RS485 Modbus-RTU protocol and support standard function codes to read turbidity values, status registers, and diagnostic information. After engineers set a unique slave address, they can access the system through a PLC serial port module or Modbus gateway. The WQS-SUITE software can be used for communication testing and register verification to accelerate integration and debugging.

Q3. How is the reliability of low turbidity measurement ensured in water samples containing bubbles or color?

AL4190S suppresses noise and stray light through pulse light modulation and narrow-band filters. AL4190 is additionally equipped with a defoaming structure and optimized light chamber design to eliminate bubble interference and reduce chromaticity effects. In actual deployment, it is recommended to perform multi-point calibration based on site water quality characteristics to ensure that the data matches process control requirements.

Q4. What are the recommendations for sensor calibration frequency and method?

Factory pre-calibration parameters support restoration at any time as a benchmark. It is recommended to perform zero and span calibration every 1-3 months according to actual operating data trends. The WQS-SUITE software provides complete calibration process guidance and supports single-point or multi-point calibration modes. Calibration records can be stored in the software to facilitate the operation and maintenance team in tracking historical changes.

Q5. How is the power supply and communication adaptability of the AL4190 series in rural drinking water or remote pump room projects?

The wide voltage input of 7-30 VDC and 0.5 W low power consumption are compatible with solar + battery power supply solutions. The RS485 interface supports long-distance bus transmission and, combined with the Modbus protocol, facilitates connection to remote RTUs or edge gateways. The fault self-diagnosis function can push abnormal status to the platform in time, reducing the frequency of on-site inspections.

Q6. What is the impact of light source life and maintenance design on long-term operating costs?

The light source design life is more than 5 years, and the AL4190 pluggable structure further simplifies replacement operations. Combined with the low-drift optical system and automatic diagnosis function, the overall maintenance requirements are low. System integrators can calculate based on lower annual replacement costs in project budgets, enhancing the competitiveness of the solution.

Summary

The Nexisense AL4190S in-situ low turbidity sensor and AL4190 low-range turbidity analyzer, relying on standardized 90° scattered light technology and targeted optical design, provide high-sensitivity, stable, and reliable turbidity measurement hardware for water supply treatment, industrial circulating water, and drinking water monitoring projects. The RS485 Modbus protocol, wide voltage and low power consumption characteristics, and complete software support make them easy to integrate into various automation and IoT systems.

Through the complementary forms of in-situ immersion and sample chamber, the project team can flexibly select models according to specific working conditions and build an efficient multi-parameter water quality monitoring network. The balanced performance of this series of products in ensuring measurement accuracy and reducing maintenance difficulty provides strong support for engineering companies and system integrators to advance water quality safety assurance projects.

If your project involves low turbidity online monitoring, water supply process control, or water treatment system integration, please feel free to contact the Nexisense technical team. We will provide professional sensor selection suggestions and system solution support according to site conditions, integration requirements, and parameter requirements to help projects land efficiently.