Zming Environmental HQ-3600 Total Nitrogen Online Analyzer
| Brand | Zming Environmental Technology Co., Ltd. |
|---|---|
| Origin | Jiangsu, China |
| Manufacturer Type | Authorized Distributor |
| Country of Origin | China |
| Model | HQ-3600 |
| Measurement Method | Alkaline Potassium Persulfate Digestion + UV Spectrophotometry |
| Measurement Range | 0–2 mg/L and 0–10 mg/L (standard), extendable up to 500 mg/L (user-configurable range) |
| Resolution | 0.001 mg/L |
Overview
The Zming Environmental HQ-3600 Total Nitrogen Online Analyzer is a fully automated, continuous-monitoring instrument engineered for precise quantification of total nitrogen (TN) in natural and anthropogenic water matrices. It operates on the standardized alkaline potassium persulfate digestion method followed by ultraviolet spectrophotometric detection at 220 nm and 275 nm—fully compliant with Chinese national standard HJ 636-2012 and technically aligned with ISO 11908:2015 (Water quality — Determination of total nitrogen — Alkaline persulfate oxidation method). The system integrates digestion, filtration, photometric measurement, and data reporting into a single robust architecture designed for unattended operation in remote or semi-permanent monitoring stations. Its modular flow path and sealed reagent handling minimize cross-contamination risk, while the integrated temperature-controlled digestion chamber ensures consistent reaction kinetics across variable ambient conditions.
Key Features
- Patented high-efficiency alkaline persulfate digestion module capable of complete TN mineralization even in turbid or particulate-laden samples (up to 500 NTU), eliminating interference from suspended solids without pre-filtration.
- Capacitive liquid-level sensing technology for precise volumetric metering of sample and reagents—achieving ≤±0.5% volume repeatability under continuous operation.
- Digital PID-controlled heating system with adjustable setpoint (120–130 °C) and real-time thermal feedback, ensuring ±0.3 °C stability during digestion for high inter-day reproducibility.
- Comprehensive hardware self-diagnostic suite including pressure sensor monitoring, peristaltic pump current profiling, leak detection via conductivity-based drip sensors, and automatic power-loss recovery with non-volatile memory retention.
- Modular design with front-accessible consumables (digestion tubes, UV cuvettes, reagent cartridges) enabling field maintenance in <15 minutes without tools.
Sample Compatibility & Compliance
The HQ-3600 accepts raw water samples directly—including surface water, municipal wastewater effluent, industrial discharge streams, estuarine mixing zones, and treated drinking water sources—without mandatory pre-filtration. It complies with data integrity requirements for environmental regulatory reporting under China’s MEP Order No. 82 and supports audit-ready operation per GLP principles. While not certified for FDA 21 CFR Part 11 out-of-the-box, its embedded event log (with timestamped operator actions, calibration records, error codes, and maintenance alerts) provides traceable digital evidence suitable for third-party validation. All wetted components are constructed from PTFE, quartz, and borosilicate glass to resist corrosion from acidic digestates and oxidizing reagents.
Software & Data Management
The analyzer runs on an embedded Linux-based controller with a web-accessible interface (HTTPS-enabled) supporting remote configuration, real-time trend visualization, and alarm threshold customization. Data output conforms to Modbus TCP and SDI-12 protocols for seamless integration into SCADA systems or central EMS platforms. Raw absorbance values (A220, A275) and calculated TN concentrations are stored locally for ≥90 days (configurable) with automatic rollover. Optional cloud synchronization enables encrypted upload to secure AWS S3 buckets, with role-based access control and TLS 1.2 encryption for all transit data. Calibration history and QC flagging (e.g., spike recovery, blank drift) are exportable as CSV or PDF reports meeting ISO/IEC 17025 documentation standards.
Applications
- Continuous monitoring of TN in river, lake, and reservoir networks for eutrophication early warning systems.
- Compliance tracking of municipal and industrial wastewater discharge permits (e.g., GB 18918-2002 Class I A limits).
- Performance evaluation of tertiary treatment units, denitrification bioreactors, and constructed wetlands.
- Long-term nutrient flux assessment at river mouths, inter-basin transfer corridors, and ecological restoration sites.
- Supporting scientific research on nitrogen cycling dynamics in urbanized watersheds and coastal transition zones.
FAQ
What digestion temperature and time does the HQ-3600 use?
The system defaults to 125 °C for 30 minutes, but temperature and duration are user-adjustable within 120–130 °C and 20–45 minutes respectively, allowing optimization for specific matrix challenges.
Can the instrument measure samples with high chloride content?
Yes—the dual-wavelength correction (220 nm/275 nm) compensates for chloride-induced absorbance interference; however, samples exceeding 2,000 mg/L Cl⁻ should be diluted prior to analysis to maintain accuracy.
Is routine maintenance required between calibrations?
Daily checks are not necessary; scheduled maintenance includes quarterly replacement of digestion tubes and UV cuvettes, biannual recalibration using NIST-traceable KNO₃ standards, and annual pump tube replacement—documented in the built-in maintenance scheduler.
Does the HQ-3600 support automatic QC checks?
Yes—it executes daily zero-blank verification, weekly multi-point calibration verification, and configurable spike recovery tests (e.g., 1 mg/L TN spike), with all results logged and alert-triggered if thresholds are exceeded.
How is data security ensured during remote access?
All remote sessions require two-factor authentication (TOTP), enforce TLS 1.2+ encryption, and restrict command execution to authenticated roles—audit logs record every login attempt, configuration change, and firmware update.
