DFRobot - RS485 Industrial Water Quality Turbidity Sensor (0-1000 NTU)

The Industrial water turbidity sensor based on the 90° light scattering principle. The probe and housing are integrated into a single unit, resulting in a simple and compact structure that is easy to use. It is designed for accurate measurement of turbidity in water, with a measurement range of 0-1000 NTU, a resolution of 0.1 NTU, and an accuracy of ±5% FS. The water turbidity sensor uses an infrared LED light source and a fiber optic light path design, incorporating a filtering algorithm to provide strong resistance to external light interference.

The turbidity sensor is equipped with an RS485 communication interface and supports the standard ModBus-RTU protocol. Tutorials are provided for connecting the sensor to an Arduino development board and DFRobot LoRaWAN Series, allowing for quick setup of a test environment and real-time data monitoring. A built-in temperature sensor provides automatic temperature compensation, ensuring accurate and reliable data output under varying environmental conditions.

The turbidity sensor is rigorously calibrated before leaving the factory and is ready for use upon arrival, requiring no further calibration. It supports two-point electrode calibration via register settings, allowing users to quickly optimize measurement accuracy after prolonged use. With an overall waterproof rating of IP68, it can be submerged in water for extended periods, making it suitable for applications such as drinking water treatment, wastewater treatment, and river and lake monitoring.

Developer Pro-Tips

• Deployment Clearances: To prevent infrared reflection and measurement errors, maintain a minimum installation clearance of 5cm from surrounding walls and ensure a 7cm obstacle-free zone directly below the sensor probe. Avoid areas with active air bubbles.
• Power Supply Routing: When interfacing with 5V MCUs (like Arduino UNO) via an RS485-to-UART module, a separate 12V supply for the sensor is only required if the system cannot supply the necessary 10~30V DC. Ensure common ground (GND) is established across the power supply, sensor, and MCU.
• ModBus Polling Optimization: Host polling intervals and wait response times must be set strictly above 200ms to prevent bus collision and data loss.
• Long-term Maintenance Protocol: For sustained accuracy, utilize deionized water (0 NTU) and a 1000 NTU standard solution for recalibration every 90 days. Always remove the black rubber protective cover prior to deployment.

Selection Guide

• Simple calibration function, supporting two-point electrode calibration
• Measurement range: 0~1000 NTU, resolution: 0.1 NTU, accuracy: ±5% FS
• Integrated probe housing design, waterproof rating up to IP68
• 90° light scattering principle with filtering algorithm, strong resistance to external light interference
• Built-in temperature sensor, automatic temperature compensation to ensure measurement accuracy
• RS485 communication interface, supporting ModBus-RTU protocol

• Wastewater Treatment Automation: Continuous monitoring of effluent clarity in industrial discharge or municipal sewage facilities to trigger automated filtration processes.
• Drinking Water Quality Assurance: Deployment in reservoir intake pipes or domestic water purification systems to verify suspended solid levels meet safety thresholds.
• Environmental IoT Node Monitoring: Integration into LoRaWAN buoy systems for real-time ecological data collection in rivers, lakes, and aquaculture ponds.
• STEM Education & Laboratory Automation: Facilitating student research in environmental engineering by connecting easily to Arduino or ESP32 development boards for data logging and analysis.

• Power Supply Voltage: 10~30V DC
• Power Consumption: 0.2W
• Communication Interface: RS485 (Standard ModBus-RTU protocol)
• Measurement Range:
           Turbidity: 0~1000 NTU
           Temperature: 0°C~+60°C
• Measurement Accuracy:
           Turbidity: ±5% FS (25℃)
           Temperature: ±0.5°C
• Resolution:
           Turbidity: 0.1 NTU
           Temperature: 0.1°C
• Temperature Compensation Range: 0°C~+60°C
• Response Time: ≤30S
• Operating Temperature: 0°C~+40°C
• Measurement Principle: 90° Light Scattering Method
• Waterproof Rating: IP68
• Pressure Resistance: 0.6MPa
• Cable Length: 5m
• Housing Material: Corrosion-resistant plastic

• RS485 Water Quality Turbidity Sensor x1
• 5m sensor cable x1