YEX-S1-TSS Online Suspended Solids Sensor | Scattered Light Method RS485 High Precision TSS Online Monitoring

YEX-S1-TSS is an industrial online suspended solids sensor for continuous TSS monitoring in wastewater treatment, sludge processing and environmental water. It uses the scattered-light (nephelometric) method with a fibre-optic optical structure to deliver 0–2000.0 mg/L readings over RS-485 Modbus RTU from a submersible IP68 probe.

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). YEX-S1-TSS belongs to the S1 tier and covers suspended-solids duty up to 2000 mg/L; for the marine-grade housing used in coastal and high-chloride plants, step up to the S1 PRO TSS sensor.

Core Technical Highlights

• Scattered-light measurement principle: the industry-standard optical method for suspended solids, measuring light scattered by particles at a defined angle rather than transmitted light — far less sensitive to lamp ageing, window fouling and colour than transmission methods.

• Fibre-optic optical structure: separates the emitter and detector from the wetted window, reducing interference from stray light and improving long-term stability in complex water matrices.

• 0–2000.0 mg/L wide range: one probe spans mixed-liquor and return-sludge concentrations, so the same model serves several process points.

• Digital RS-485 Modbus RTU: one twisted pair carries TSS and temperature to PLC, RTU, datalogger or IoT gateway with register-level diagnostics.

• IP68 submersible body: continuous immersion in aeration basins, clarifiers, channels and tanks; NPT 3/4 thread for pipe and flow-cell mounting.

• 12–24 V DC: compatible with solar-powered stations and standard control-cabinet supplies.

Application Scenarios

1. Wastewater treatment process control: monitor mixed-liquor suspended solids (MLSS) to tune sludge age, return-sludge rate and wasting schedule.

2. Sludge processing: track thickened and digested sludge concentration to optimise dewatering polymer dosing.

3. Effluent quality assurance: verify that final effluent solids stay inside permit limits and flag clarifier upsets immediately.

4. Environmental and industrial water: monitor sediment transport, dredging plumes and solids loading in rivers, canals and industrial intake water.

Technical Specifications

Contact our engineering team for the full datasheet, calibration-suspension procedure and register map before ordering.

Frequently Asked Questions

TSS vs. turbidity — which parameter do I actually need?

Both use optical scattering, but they answer different questions. Turbidity (NTU/FNU) is an optical property used chiefly for drinking-water clarity and filtration control. TSS (mg/L) is a gravimetric mass concentration used for process sludge and discharge permits. If your target is written in mg/L against a permit limit, choose TSS; if it is written in NTU, choose a turbidity sensor.

How is the sensor calibrated?

The standard method is a two-point calibration using formazin or a comparable certified suspension standard, cross-checked against a gravimetric laboratory analysis of a real sample. Because particle size and colour affect the optical response, the most accurate practice is to apply a site-specific correlation factor derived from several laboratory comparisons of your own water.

Will fouling affect the measurement?

Any optical sensor needs a clean optical window. The fibre-optic structure and scattering principle reduce sensitivity to window haze compared with transmission methods, but in high-solids or greasy streams you should schedule periodic manual cleaning. Cleaning frequency is the single largest factor in long-term TSS data quality.

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 suspended-solids monitoring project? Send us your concentration range, particle characteristics and control-system interface — our engineers will return a configuration proposal, Modbus register map and quotation within one business day.