YST Turbidimeter & Sludge Concentration Meter YST108B-NTU680T

Overview

The YST Turbidimeter & Sludge Concentration Meter YST108B-NTU680T is an industrial-grade optical sensor engineered for continuous, real-time measurement of turbidity (in NTU) and suspended solids concentration (in g/L) in aqueous process streams. Based on the ISO 7027-compliant 860 nm infrared LED light source, the instrument employs a dual-optical-path principle—simultaneously detecting both scattered and transmitted light intensities—to mitigate common interferences such as air bubbles, biofilm deposition, and particulate fouling. This dual-signal architecture enables robust compensation algorithms that maintain measurement stability under dynamic hydraulic conditions, including rapid turbidity spikes during stormwater inflow or sludge blanket fluctuations in clarifiers. Designed specifically for unattended operation in municipal wastewater treatment plants, rural water supply systems, hospital effluent monitoring, and industrial pretreatment units, the YST108B-NTU680T delivers traceable, auditable data aligned with environmental compliance frameworks including China’s HJ/T 92–2019 and international best practices for continuous emission monitoring systems (CEMS).

Key Features

• Dual-optical-path measurement architecture (90° scattered light + forward-transmitted light) for enhanced interference rejection and long-term signal stability
• ISO 7027-certified 860 nm infrared LED source ensures spectral consistency, minimizes color interference, and avoids photobiological effects in UV-sensitive applications
• IP67-rated stainless steel housing with chemical-resistant optical windows, suitable for submersible deployment in raw influent channels, activated sludge basins, and disinfection contact tanks
• Modular power architecture supporting AC 220 V, DC 24 V, and solar-battery hybrid configurations—enabling deployment in off-grid rural water stations
• Configurable analog (4–20 mA) and digital (RS485 Modbus RTU) outputs for seamless integration into SCADA, DCS, PLC, and cloud-based telemetry platforms
• Remote calibration support via two-point manual standardization using formazin or AMCO-AE reference suspensions; no field disassembly required

Sample Compatibility & Compliance

The YST108B-NTU680T is validated for use across a broad spectrum of aqueous matrices, including potable water, secondary effluent, anaerobic digester supernatant, hospital wastewater, and surface water with high organic loading. Its optical design accommodates variable particle size distributions—from fine colloidal clays (<1 µm) to coarse floc aggregates (>100 µm)—without requiring user-selectable wavelength or scattering angle adjustments. The device complies with ISO 7027:2016 for turbidity methodology and meets mechanical and electrical safety requirements per IEC 61000-6-2 (immunity) and IEC 61000-6-4 (emissions). Data integrity conforms to GLP-aligned logging protocols, with timestamped measurements stored locally (optional SD card module) and transmitted with embedded CRC checksums. While not certified to FDA 21 CFR Part 11 out-of-the-box, audit trail functionality—including operator ID, calibration event logs, and parameter change history—can be enabled through firmware configuration for regulated environments.

Software & Data Management

The meter operates autonomously without embedded software dependencies. Configuration, calibration, and diagnostics are performed via ASCII command set over RS485 or through optional web-enabled gateway modules (e.g., YST-GW4G). All measurement data include UTC timestamps, sensor temperature, signal-to-noise ratio indicators, and diagnostic flags (e.g., “window dirty”, “low light intensity”). When integrated with third-party SCADA systems, the device supports Modbus register mapping for real-time polling of primary and secondary variables—including compensated turbidity, estimated SS concentration, and internal sensor health metrics. Historical datasets export in CSV format with ISO 8601 timestamps, facilitating trend analysis in tools such as MATLAB, Python Pandas, or commercial BI dashboards. Firmware updates are delivered via secure HTTP(S) endpoints with SHA-256 signature verification to ensure supply chain integrity.

Applications

• Municipal Wastewater Treatment: Real-time monitoring at final effluent discharge points to enforce Class I-A regulatory limits; automated alarm triggering for turbidity excursions above threshold values (e.g., ≥8 NTU)
• Rural Drinking Water Systems: Remote surveillance of filtered groundwater or surface water supplies, with SMS alerts via 4G telemetry for early detection of filter breakthrough or pump seal failure
• Hospital Effluent Control: Integration with UV or chlorine dosing systems to extend disinfection residence time when turbidity exceeds 5 NTU—ensuring pathogen inactivation efficacy per WHO guidelines
• Industrial Pretreatment Monitoring: Tracking suspended solids in cooling tower blowdown, food processing rinse water, or textile dye bath recirculation loops to optimize coagulant dosing and reduce sludge generation
• Research & Pilot-Scale Studies: High-frequency turbidity profiling in membrane bioreactors (MBRs) or dissolved air flotation (DAF) units to correlate optical density with MLSS and settleability indices

FAQ

What calibration standards are recommended for field verification?
Formazin suspension (primary standard per ISO 7027) or AMCO-AE polymer standard (secondary standard) at 10 NTU and 100 NTU concentrations are advised for two-point validation. Calibration intervals should align with local regulatory guidance—typically every 30 days for critical discharge monitoring.
Can the sensor be installed in pressurized pipelines?
Yes—the inline mounting kit includes NPT or DIN flange adapters rated for up to 6 bar working pressure. For submersible use, the 50 m cable option supports deep-well or reservoir deployments with optional weighted sinker assembly.
Does the device support automatic temperature compensation?
Yes—integrated Pt1000 RTD measures sensor head temperature continuously and applies polynomial correction to turbidity readings per ISO 7027 Annex B.
Is Modbus TCP supported, or only Modbus RTU over RS485?
The base unit implements Modbus RTU over RS485. Modbus TCP is available via optional YST-GW4G Ethernet-to-Modbus gateway, which also provides MQTT/HTTP(S) cloud upload capability.
How is fouling of the optical windows managed during extended deployment?
The sensor features a self-diagnostic window contamination algorithm based on signal attenuation rate. Users may schedule periodic manual cleaning or integrate with ultrasonic wiper accessories (YST-WP100) for fully automated maintenance cycles.