Water quality is non-negotiable—whether you’re running a municipal water treatment plant, managing an industrial facility’s wastewater discharge, or operating an aquaculture farm. Among all water quality parameters, turbidity stands out as one of the most critical indicators of water clarity and safety. But traditional grab sampling simply cannot keep up with today’s regulatory demands and operational needs.
This guide explains how online turbidity analyzers work, why they are essential for compliance and efficiency, and how to select the right solution for your application.
Turbidity measures the cloudiness or haziness of a liquid caused by suspended particles (silt, sediment, microorganisms, industrial effluents, etc.). High turbidity may indicate contamination, reduce disinfection efficiency, and harm aquatic ecosystems.
An online turbidity analyzer is an automated instrument that provides continuous, real-time measurement, eliminates manual sampling intervals, and transmits data directly to SCADA, PLC, or cloud platforms.
Drinking water treatment plant effluents (USEPA / WHO compliance)
Wastewater treatment plant discharges (NPDES permits)
Industrial process water recirculation loops
Aquaculture tank and recirculating systems
River, lake, and surface water monitoring stations
Raw water intake and filter breakthrough detection
The global water quality analyzer market was valued at approximately US$$4.5 billion in 2025** and is projected to reach *$$7.3 billion by 2035 (CAGR 5%). Driven by stricter regulations and industrial automation, the online turbidity segment continues strong growth.
Most industrial online turbidity analyzers use the nephelometry principle: measuring light scattered by suspended particles at a 90° angle to the incident light beam. This method is recommended by ISO 7027 and widely accepted for global regulatory compliance.
Advanced sensors integrate precision optics, stable infrared LEDs, and digital signal processing to maintain accuracy under varying ambient light and temperature.
Measurement range: Low‑range (0–40 NTU) / High‑range (up to 4000 NTU+)
Resolution: 0.01 NTU or better for ultra‑low monitoring
Output interfaces: 4–20 mA analog + RS485 (Modbus RTU)
Housing material: 316 stainless steel for corrosion resistance
Ingress protection: Minimum IP68 for submerged/outdoor use
Self-cleaning: Wiper or air‑bubble cleaning to reduce maintenance
Drinking water: typically 0–1 NTU
Wastewater / aquaculture: 0–1000 NTU or higher
Accuracy directly determines reliable compliance detection
Verify compliance with:
ISO 7027 (infrared nephelometric method)
USEPA Method 180.1 (white light turbidity) Many regions require ISO‑compliant instruments for official reporting.
For harsh environments (wastewater, industrial effluent, seawater):
316 stainless steel provides superior corrosion resistance vs. plastic/POM, extending service life and lowering replacement costs.
4–20 mA: for legacy PLC systems
RS485 (Modbus RTU/ASCII): for modern digital networks
Supports cloud/SCADA logging for remote monitoring and trend analysis
Immersion (light‑shielded) design for open channels/tanks
Automatic cleaning (wiper / bubble)
Quick calibration procedures Reduces downtime and total cost of ownership.
Designed for performance, durability, and cost‑effectiveness, the ERUN‑B6B delivers stable real‑time turbidity measurement for diverse water quality applications.
Built on ISO 7027 90° scattered light with precision optical components, effectively rejecting ambient light interference.
Parameter | Specification |
Measuring Range | 10 ~ 4,000 NTU |
Measuring Principle | ISO 7027 compliant, 90° scattering method |
Accuracy | ±5.0% of full scale |
Resolution | 0.01 NTU |
Temperature Measurement | 0.0 ~ 60.0°C |
Housing Material | 316 stainless steel |
IP Rating | IP68 (fully submersible) |
Output Signals | 4‑20 mA analog + RS485 digital |
Power Supply | DC 9 ~ 30 V |
Pressure Range | 0 ~ 2 bar |
ISO 7027 compliant for global regulatory acceptance
316 stainless steel housing for harsh wastewater/industrial environments
Wide 4,000 NTU range covers drinking water to high‑load wastewater
Dual analog + digital outputs for flexible PLC/SCADA integration
IP68 submersible for tanks, channels, rivers, aeration basins
Light‑shielded immersion design reduces maintenance
0.01 NTU resolution detects subtle water quality changes
Drinking water and tap water treatment facilities
Domestic and industrial wastewater treatment plants
Aquaculture and fish farming systems
River and surface water environmental monitoring stations
Swimming pools and recreational water facilities
Industrial process water and cooling tower makeup
