YEX-S1-CL Online Residual Chlorine Sensor RS485 Modbus

YEX-S1-CL is an industrial online residual chlorine sensor for continuous disinfection control in drinking water, swimming pools, cooling water and secondary supply systems. It reports residual chlorine and temperature over RS-485 Modbus RTU from a submersible IP68 probe with a 0–2.000 mg/L range matched to typical disinfection residuals.

Where It Fits in the YexSensor Line

The YexSensor online water quality family is organized in three tiers: the S1 standard series (cost-effective probes in an IP68 engineering-plastic housing for high-volume monitoring points), the S1 PRO stainless-steel series (316L stainless-steel housings for seawater, high-chloride and oily duty), and the S2 flagship series (dual-interface RS485 + 4–20 mA connectivity for OEM and mixed analog/digital projects). If your duty is conventional municipal, industrial or agricultural water at scale, the S1 series is the economical choice; specify S1 PRO when corrosion resistance and higher accuracy are required.

Core Technical Highlights

• 0–2.000 mg/L range: matched to the working window of drinking water, pools and cooling-water disinfection residuals.

• Built-in temperature channel: temperature-compensated readings for stable dosing control.

• Digital RS-485 Modbus RTU: one twisted pair to PLC, RTU or datalogger — disinfection data straight into SCADA records.

• IP68 submersible body: tanks, basins and pipelines; NPT 3/4 thread for pipes and flow cells.

• 12–24 V DC: standard cabinet and solar-station supply.

Application Scenarios

Drinking water and secondary supply:

1. guard disinfection residual across tanks and networks.

Swimming pools:

2. continuous residual feedback for dosing pumps.

Cooling water:

3. biocide dosing control and biofouling prevention.

Food and process washing:

4. sanitizer-residual verification in wash-water loops.

Technical Specifications

Contact our engineering team for the full datasheet and register map before ordering.

Frequently Asked Questions

Free chlorine, total chlorine — what does the probe report?

Confirm the analytical definition your control or permit actually needs before ordering: free residual chlorine, total chlorine and hypochlorous acid are not interchangeable. Our engineers will match the measuring cell and any compensation to your definition.

Does pH affect the reading?

Chlorine chemistry is pH-dependent. For stable dosing control, log pH alongside chlorine (many stations run our pH probe on the same Modbus bus) and verify against your reference method at commissioning.

What information should I provide for a quotation?

Provide the water matrix, expected residual span, pH range, installation method, cable distance, power supply and Modbus integration requirements, plus quantity and destination country.

What quality assurance is provided?

Every unit passes a standardized inspection process and a 72-hour high-temperature aging test before shipment, and is backed by a one-year warranty from the date of sale. Standard delivery includes the sensor, a 5 m four-core shielded cable, an instruction manual and a certificate of conformity.

Planning a residual chlorine monitoring project? Send us your water matrix, range and control-system interface — our engineers will return a configuration proposal, Modbus register map and quotation within one business day.