Chemins TN-300C Online Total Nitrogen Analyzer

Overview

The Chemins TN-300C Online Total Nitrogen Analyzer is a fully automated, laboratory-grade instrument engineered for continuous, real-time quantification of total nitrogen (TN) in aqueous environmental samples—including raw sewage, treated effluent, surface water, and industrial wastewater. It operates on a validated, modified chromotropic acid spectrophotometric method compliant with ISO 11905-1 (Water quality — Determination of nitrogen — Part 1: Total nitrogen by oxidation with alkaline persulfate) and aligned with EPA Method 351.2 principles. The measurement sequence begins with high-temperature (120–124 °C), alkaline potassium persulfate digestion—converting organic nitrogen, ammonia, nitrite, and nitrate into nitrate-nitrogen. Following neutralization and acidification, the resulting nitrate reacts with a proprietary chromogenic reagent under strongly acidic conditions to form a stable yellow-brown complex. Absorbance is measured precisely at 420 nm using a dual-beam optical system with temperature-stabilized LED source and matched photodetector, minimizing drift and compensating for lamp aging or cuvette fouling.

Key Features

• Advanced photometric quantification engine with integrated optical zeroing and path-length correction—eliminates interference from sample color, turbidity (>200 NTU), suspended solids, and microbubbles without filtration or dilution.
• Single-channel, high-integration solenoid valve manifold with chemically resistant PTFE/PEEK fluidic pathways—reducing carryover, enabling rapid reagent exchange, and supporting <5-minute maintenance cycles.
• Intelligent self-diagnostic architecture: real-time monitoring of digestion temperature, reagent depletion, pump performance, optical integrity, and flow status—with automatic fault logging and event-triggered alerts.
• Full automation suite: auto-cleaning (air-pulse + chemical rinse), auto-calibration (multi-point standard verification), scheduled measurement (hourly, daily, or custom intervals), and external trigger support via dry-contact or Modbus RTU.
• Robust data continuity: built-in non-volatile memory retains >3 years of timestamped results, calibration logs, error records, and diagnostic snapshots—even during power interruption; auto-resume operation upon recovery.
• Remote operational readiness: embedded Ethernet and optional 4G LTE module enable secure, encrypted access via HTTPS-based web interface or SCADA integration (Modbus TCP/RTU, OPC UA).

Sample Compatibility & Compliance

The TN-300C accepts unfiltered liquid samples with pH 4–10 and conductivity ≤5 mS/cm. It is certified for use in municipal wastewater treatment plants (WWTPs), drinking water pre-treatment monitoring, river basin surveillance networks, and industrial discharge compliance reporting. Its analytical performance meets ISO/IEC 17025 requirements for routine environmental testing laboratories and supports GLP/GMP data integrity protocols—including full audit trail, electronic signature capability, and FDA 21 CFR Part 11-compliant user access control when deployed with Chemins’ optional SecureLog™ software package.

Software & Data Management

The analyzer runs on Chemins’ embedded Linux-based firmware (v4.2+) with a responsive HTML5 web interface accessible via any modern browser. Data export supports CSV, PDF report generation, and direct transmission to LIMS or cloud platforms (AWS IoT Core, Azure IoT Hub) via TLS 1.2 encryption. All measurements include metadata: digestion time, blank absorbance, calibration slope/R², reagent lot traceability, and operator ID. Historical datasets are queryable by date range, alarm type, or QC flag—and can be exported with ISO 14040-aligned uncertainty estimates derived from internal precision validation (n=12, RSD <2.1% at 2 mg/L TN).

Applications

• Continuous compliance monitoring per EU Urban Wastewater Treatment Directive (91/271/EEC) and China’s GB 18918-2002 discharge standards.
• Process optimization in biological nutrient removal (BNR) systems—tracking TN load variations across anoxic/oxic zones.
• Early-warning detection of nitrification failure or denitrification inhibition in activated sludge basins.
• Source tracking in watershed management programs—correlating TN spikes with rainfall events or agricultural runoff periods.
• Long-term trend analysis for regulatory reporting under national environmental information systems (e.g., China’s National Environmental Monitoring Network).

FAQ

What digestion temperature and duration does the TN-300C use?
The instrument maintains a precise 122 ±1 °C digestion temperature for 30 minutes—validated against reference methods per ISO 11905-1.
Does it require manual sample filtration?
No—its optical design and digestion chemistry tolerate turbid samples up to 200 NTU without pre-filtration.
How often must reagents be replaced?
Standard reagent kits (alkaline persulfate, acidifier, chromogenic agent) last 30 days at hourly measurement frequency; onboard level sensors trigger low-reagent alerts 72 hours in advance.
Can it integrate with existing SCADA or DCS systems?
Yes—via native Modbus RTU (RS-485), Modbus TCP (Ethernet), or optional OPC UA server mode with configurable polling intervals and alarm mapping.
Is remote firmware update supported?
Yes—secure over-the-air (OTA) updates are performed via signed package deployment through the web interface, with rollback capability and versioned changelogs.