This Online Digital Residual Chlorine Sensor adopts advanced membrane-free amperometric technology to monitor free residual chlorine in water in real time. Integrated temperature and pH automatic compensation, effectively eliminates water quality interference and ensures accurate readings.
Built-in digital signal processing, standard RS485 Modbus-RTU output, plug-and-play with controllers, PLC and IoT systems. IP68 submersible design, 3/4" NPT thread for easy installation. No reagents or consumables required, low maintenance and long service life for 24/7 continuous operation.
Online Digital Residual Chlorine Sensor is a dedicated digital probe for real-time monitoring of residual chlorine in water. Adopting advanced electrochemical principle, it delivers fast response and high accuracy for chlorine concentration in disinfected water.


Built-in temperature compensation effectively reduces measurement deviation caused by temperature change. It outputs standard RS485 MODBUS-RTU signal, which can be directly connected to controllers, PLC and remote monitoring platforms for easy data acquisition.
The sensor is equipped with anti-contamination diaphragm and fully sealed IP68 structure. It resists dirt and corrosion, and requires little maintenance during long-term submerged operation.
It is widely used in waterworks, swimming pools, reclaimed water systems, industrial disinfection water, municipal pipe network and environmental water quality monitoring.
Standard Flow Cell (YA-26-2) Included
Product Features
1.RS-485 transmission interface with MODBUS-RTU communication protocol, supporting bidirectional communication.
2.Isolated power supply and output design to ensure electrical safety.
3.Built-in protection circuit enhances anti-interference capability, making it suitable for complex environments.
4.Simple and user-friendly communication protocol, capable of outputting more electrode diagnostic information for greater intelligence.
5.Low-power design for broader application scenarios; internal memory retains calibration and settings during power outages.

Technical Specifications
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Free Chlorine |
Measurement Range | |
00.00mg/L~20.00 mg/L |
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Resolution |
0.01 mg/L |
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Accuracy |
±5%F.S. |
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Temperature |
Measurement Range |
-10.0~110.0℃ |
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Resolution |
0.1℃ |
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Accuracy |
±0.5℃ |
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Sensor Type |
Thermistor TH10K |
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Compensation |
Automatic/Manual |
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Data Transmission |
RS-485 |
MODBUS-RTU Communication Protocol |
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Other Parameters |
Power Supply |
9~27VDC |
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Isolation Strength |
2500Vrms |
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Power Consumption |
Approx 0.5W |
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Material |
Stainless Steel Housing, Platinum Sensor |
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Installation Method |
PG13.5 Thread |



Applications
Municipal Water Management
Tracking safe disinfection residual levels inside drinking water treatment plants and distribution networks.
Commercial Pools & Spas
Driving automated chlorination control loops to keep swimming water safe and compliant.
Food & Beverage Processing
Monitoring sanitization spray barriers during wash sequences for fresh produce or containers.
Industrial Wastewater
Regulating de-chlorination loops in hospital effluents or cooling tower circulation water before discharge
Product Application










