Dragino DR-CL | Integrated Residual Chlorine Sensor (RS485)

The Dragino DR-CL is an integrated residual chlorine sensor that measures free (residual) chlorine in water and outputs readings over RS485 (Modbus-RTU). It is designed to connect to the Dragino WQS-series water quality transmitter (sold separately), which uploads the data to a LoRaWAN, NB-IoT or CAT-M1 server for remote monitoring. It is available in two measurement ranges - DR-CL-2ML (0-2 mg/L) for low-chlorine applications such as drinking water, and DR-CL-10ML (0-10 mg/L) for higher-concentration applications - both with 0.01 mg/L resolution and an IP68, pressure-rated build for demanding water environments. Key Features Residual Chlorine MeasurementContinuously measures free chlorine in water with 0.01 mg/L resolution and ±5% FS accuracy. Two Range OptionsChoose 0-2 mg/L (DR-CL-2ML) for low-level monitoring or 0-10 mg/L (DR-CL-10ML) for higher concentrations. RS485 Modbus OutputStandard RS485 Modbus-RTU at 9600 baud connects directly to the Dragino WQS transmitter or any Modbus controller. Rugged & SubmersibleIP68-rated with 0.6 MPa pressure resistance and low 0.19 W power draw for long-term field deployment. Typical Applications •Drinking & tap water: verify disinfection levels in distribution networks (DR-CL-2ML). •Water treatment & wastewater: monitor chlorine dosing in treatment plants. •Industrial & pool water: track higher chlorine concentrations (DR-CL-10ML). Available Models Model Chlorine Range Resolution DR-CL-2ML 0 - 2 mg/L 0.01 mg/L DR-CL-10ML 0 - 10 mg/L 0.01 mg/L Technical Integration •Measured parameter: Free / residual chlorine, ±5% FS accuracy, 0.01 mg/L resolution •Ranges: DR-CL-2ML: 0-2 mg/L | DR-CL-10ML: 0-10 mg/L •Output: RS485, Modbus-RTU, 9600 baud rate •Power: DC 7-30 V; consumption 0.19 W •Water conditions: Temperature 0-50 °C; pH 4-9; flow rate 30-60 L/h (flow-channel installation) •Protection: IP68; pressure resistance 0.6 MPa •System: Connects to the Dragino WQS-series water-quality transmitter (sold separately) for LoRaWAN / NB-IoT / CAT-M1 uplink •Setup help: For probe selection or WQS transmitter pairing, contact the shopioT technical team Frequently Asked Questions What is the difference between DR-CL-2ML and DR-CL-10ML? Only the measurement range: 0-2 mg/L versus 0-10 mg/L. All other specifications are identical. Does it work on its own? No - it is a probe that connects via RS485 to the Dragino WQS-series transmitter (sold separately), or to any Modbus-RTU controller. How is it installed? Via a flow channel with a recommended flow rate of 30-60 L/h, in water at 0-50 °C and pH 4-9. Monitoring Water Quality? Talk To Our IoT TeamShop Dragino