S461 – Optical Turbidity Sensor

The S461/T optical infrared sensor is designed for operational turbidity measurements in municipal and industrial wastewater treatment plants, for monitoring surface water pollution, and for various industrial applications.

Nephelometric measurement principle (side-scattering, ISO 7027, 90°)
2 measurement ranges: 0–10 NTU, 0–100 NTU (S461/LT) or 0–1,000 NTU and 0–4,000 NTU (S461/TN)
Rugged design suitable for continuous submersion (IP68)
Modbus-RTU digital output via RS-485
Very low current consumption, even for battery-powered applications (turbidity monitoring of lakes, ponds, rivers, and streams)
Calibration using standard formazine solutions
Compatible with FIEDLER control units (M2001, E2, H3, H7)

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Description

The sensor can be connected to FIEDLER telemetry or data-logging stations via the built-in RS485 communication interface, allowing for the acquisition of a time-series record of turbidity and the control of downstream equipment (control units) based on the measured values.
For stations with a built-in GSM module, warning text messages can be automatically sent when the preset threshold values for turbidity are exceeded.

Applications

Operational turbidity measurements in municipal and industrial wastewater treatment plants
Monitoring of surface water pollution
Municipal wastewater treatment (inlet/outlet checks)
Remediation network
Drinking water

Technical specifications

Technical Specifications	S461 - Optical Turbidity Sensor
Measurement Principle	90° nephelometric measurement, ISO 7027 / EN 27027
Measurement Ranges S461/LT	0 to 10 NTU and 0 to 100 NTU
Measurement Ranges for S461/TN	0–1,000 and 0 to 4,000 NTU
Resolution	0.01 to 1 NTU
Measurement Accuracy	Better than 5% of range
Operating Temperature	0 °C to +50 °C
Storage Temperature	-10 °C to +60 °C
Communication interface	Modbus RTU over RS485
Maximum response time	< 5 sec (90% of measured value)
Supply voltage	12 to 24 V DC
Power consumption	< 3 W
Dimensions	diameter 42 mm, length 231 mm
Weight	1460 g (sensor with 10 m cable)
Maximum Allowable Pressure	4 bar
Connection	10 m polyurethane cable terminated with an M12/5 connector (pins)
Sensor Material	PVC, AISI 316
Protection rating	IP68

Downloads

Price List Cenik 2026 V101 Chemitec S461 Lt Turbidity Sensor Pvc Body S461 Tn Sonda Torbidit 0 1000 0 4000ntu Multi 1 S461lt Manual Turbidity Probe S461 Tn 1 Datasheet H7 0 Datasheet M2001e Datasheet Rizeni Cov Datasheet E2 0