Leici DGB-402F Portable Residual and Total Chlorine Analyzer

Overview

The Leici DGB-402F Portable Residual and Total Chlorine Analyzer is a field-deployable spectrophotometric instrument engineered for precise, on-site quantification of free residual chlorine and total chlorine in aqueous samples. It operates on the standardized N,N-diethyl-p-phenylenediamine (DPD) colorimetric method—recognized in ISO 7393-2, APHA Standard Methods 4500-Cl G, and Chinese national standard HJ 586–2010. The system employs a stable 515 nm LED light source with narrow spectral bandwidth to ensure high photometric reproducibility and minimal drift over extended operation. Unlike benchtop analyzers requiring laboratory infrastructure, the DGB-402F integrates optical path alignment, temperature-compensated detection, and microprocessor-controlled endpoint recognition into a compact, rugged chassis—enabling reliable measurements under variable ambient conditions without external calibration standards at point-of-use.

Key Features

• High-contrast 3.5-inch color LCD display with adjustable backlight and auto-dimming functionality for readability in direct sunlight or low-light environments
• Integrated 515 nm LED optical module with >10,000-hour service life and factory-aligned collimation optics
• Automated endpoint detection algorithm that identifies reaction completion based on kinetic absorbance stabilization—eliminating subjective timing errors
• On-device dilution factor configuration with automatic concentration back-calculation; supports up to 10× manual dilution input
• Flexible calibration architecture: preloaded factory curves for residual/total chlorine, full reset capability, and user-defined 1–3 point calibration using traceable DPD reagents
• GLP-compliant data management: timestamped entries with operator ID tagging (via optional software), audit trail logging, and non-volatile memory retention
• IP65-rated enclosure with sealed keypad and gasketed battery compartment—certified for dust resistance and water jet protection during field transport and outdoor sampling
• Dual-interface connectivity: USB 2.0 for PC synchronization via Leici LabLink™ desktop software (Windows/macOS compatible); RS-232 port for direct thermal printer output (e.g., Epson TM-T20II)

Sample Compatibility & Compliance

The DGB-402F is validated for use across diverse water matrices including potable water, swimming pool circulation systems, cooling tower effluents, hospital wastewater discharge streams, and municipal distribution network taps. Its DPD chemistry demonstrates robustness against common interferences such as monochloramine (at typical disinfection doses), nitrite (<0.3 mg/L), and turbidity (<5 NTU). For regulatory compliance, the instrument meets functional requirements outlined in US EPA Method 334.0 and EU Standard EN ISO 7393-2. While not FDA 21 CFR Part 11 certified out-of-the-box, its data export protocol (CSV/Excel) supports integration into validated LIMS environments where electronic signatures and audit trails are managed at the enterprise level. All onboard storage adheres to GLP principles—including immutable timestamps, sequence-numbered records, and no overwrite capability without explicit user confirmation.

Software & Data Management

Leici LabLink™ software enables secure bidirectional communication between the DGB-402F and host computers. Users can export raw absorbance values, calculated concentrations, calibration coefficients, and metadata (date/time, operator ID, sample ID, dilution factor) in ISO-standard CSV format. The software includes tools for statistical review (mean, SD, CV%), trend charting across time-series datasets, and batch report generation compliant with internal QA/QC protocols. Data integrity safeguards include encrypted local database storage, password-protected configuration changes, and version-stamped firmware updates traceable to Leici’s official release repository. No cloud upload or telemetry functions are implemented—ensuring full data sovereignty for regulated laboratories.

Applications

• Routine verification of residual chlorine levels in drinking water distribution networks per WHO Guidelines for Drinking-water Quality (4th Ed.)
• Swimming pool and spa facility compliance monitoring aligned with CDC Model Aquatic Health Code (MAHC) Section 6.004
• Validation of disinfection efficacy in healthcare wastewater treatment prior to environmental discharge
• Field verification of chlorine dosing systems during emergency response (e.g., post-flooding water safety assessments)
• Quality control of sodium hypochlorite stock solutions in pharmaceutical cleanroom utilities
• Educational laboratory instruction on redox-based water quality indicators and spectrophotometric methodology

FAQ

What reagents are required for routine operation?
The DGB-402F requires two proprietary DPD-based reagent kits: one for residual chlorine (DGB-RC-KIT) and one for total chlorine (DGB-TC-KIT). Both are supplied as stabilized powder tablets with desiccant packaging; shelf life is 24 months unopened at room temperature.
Can the instrument measure chlorine dioxide simultaneously?
No—the DGB-402F is optimized exclusively for DPD-based chlorine species. Chlorine dioxide quantification requires a separate method (e.g., amperometric titration or Lissamine Green B spectrophotometry) and is not supported by this model.
Is calibration verification traceable to NIST standards?
While the instrument itself does not include NIST-traceable reference materials, Leici provides optional certified DPD calibration standards (Cat. No. DGB-CAL-STD-1000) with certificate of analysis referencing NIST SRM 3100 series for user-performed verification.
How often must the optical path be cleaned or serviced?
The fixed-path 25 mm cuvette holder requires no routine optical alignment. Users should wipe the LED window and detector lens weekly with lint-free optical tissue moistened with isopropanol; full service interval is recommended every 24 months or after 10,000 measurements, whichever occurs first.
Does the device support multi-language UI?
The embedded firmware supports English and Simplified Chinese interfaces only; no additional language packs are available.