Leici DDBJ-350F Portable Conductivity Meter

Overview

The Leici DDBJ-350F Portable Conductivity Meter is a high-precision, multi-parameter electrochemical analyzer engineered for field-deployable and laboratory-based conductivity, resistivity, total dissolved solids (TDS), salinity, and temperature measurements. It operates on the principle of two-electrode AC conductometric measurement, applying a low-frequency alternating current to minimize polarization effects and electrode fouling—critical for reproducible results across diverse aqueous matrices. Designed to meet routine quality control, environmental monitoring, and process verification requirements, the instrument delivers traceable, GLP-compliant data without sacrificing portability or operational robustness. Its compact form factor (90 × 255 × 40 mm, 0.5 kg), IP65-rated enclosure, and integrated lithium-ion power system enable reliable use in humid labs, cleanrooms, wastewater treatment facilities, and outdoor sampling sites.

Key Features

• High-resolution 4.3-inch color TFT touchscreen with adjustable backlight and intuitive icon-driven navigation—optimized for gloved operation and low-light environments.
• Auto-ranging measurement architecture with dynamic resolution switching: 0.001 µS/cm minimum at low-conductivity ranges, scaling appropriately up to 1000 mS/cm without manual range selection.
• Intelligent endpoint detection algorithms support multiple read modes: auto-hold stabilization, timed interval logging (1–999 s), scheduled sampling, and manual capture—reducing operator variability.
• Comprehensive temperature compensation suite: user-selectable reference temperatures (20 °C or 25 °C), linear coefficient adjustment, and dedicated pure-water mode compliant with ISO 7888 and ASTM D1125 for ultrapure water applications.
• Automatic frequency switching (1 kHz / 10 kHz / 100 kHz) ensures optimal signal-to-noise ratio across full conductivity span; compatible with standardized cell constants (K = 0.01, 0.1, 1.0 cm⁻¹) and auto-identifies GB-standard calibration solutions (1413 µS/cm, 12.88 mS/cm, etc.).
• Integrated data integrity safeguards: timestamped storage of 1000 records per parameter, audit-trail-capable metadata (operator ID, calibration history, electrode serial), and battery-level warnings with charging status feedback.

Sample Compatibility & Compliance

The DDBJ-350F accommodates a broad spectrum of liquid samples—from deionized water and pharmaceutical buffers to brines, seawater analogs, and industrial effluents—without requiring hardware modification. Its dual-range resistivity capability (5.00 Ω·cm to 20.00 MΩ·cm) supports validation of water purification systems per USP and EP 2.2.38. The instrument complies with IEC 61010-1 for electrical safety and meets IP65 ingress protection standards for dust-tight and low-pressure water jet resistance. All measurement protocols align with ISO/IEC 17025 documentation requirements, and calibration traceability is maintained through NIST-traceable GB standard solutions. Firmware architecture supports future regulatory alignment—including configurable electronic signatures and secure user access levels required under FDA 21 CFR Part 11 for regulated laboratories.

Software & Data Management

Data export and management are facilitated via native USB Type-B and RS-232 interfaces. A dedicated Windows-compatible communication software enables bidirectional data transfer, batch calibration report generation, and customizable print templates (including GLP header fields: date/time, operator, instrument ID, electrode SN). Stored datasets include raw sensor output, compensated values, temperature readings, and calibration coefficients—each tagged with unique identifiers for full chain-of-custody traceability. The software supports CSV and PDF export formats compatible with LIMS integration and internal QA/QC review workflows. No cloud dependency or vendor-locked firmware updates: all upgrades are delivered as signed .bin files with checksum validation to ensure integrity during installation.

Applications

• Environmental field testing: surface water conductivity profiling, groundwater salinity mapping, and stormwater runoff screening per EPA Method 120.1.
• Pharmaceutical manufacturing: WFI (Water for Injection) and PW (Purified Water) resistivity verification per USP , including temperature-compensated pass/fail assessment against 1.3 MΩ·cm (25 °C) thresholds.
• Food & beverage QC: brine concentration control in canning operations, dairy processing conductivity checks, and desalination plant feedwater monitoring.
• Academic teaching labs: hands-on instruction in solution conductivity theory, Kohlrausch’s law, and temperature dependence modeling.
• Industrial maintenance: cooling tower water cycle analysis, boiler feedwater purity audits, and RO membrane performance trending.

FAQ

What calibration standards does the DDBJ-350F recognize automatically?

It identifies four GB-defined conductivity standards (e.g., 1413 µS/cm, 12.88 mS/cm) without manual entry—enabling rapid 1–3 point calibration with minimal procedural error.
Can the instrument measure ultrapure water accurately?

Yes—when paired with a K = 0.01 cm⁻¹ cell and using pure-water compensation mode, it meets ISO 3696 Grade 1 specifications for resistivity measurement up to 18.2 MΩ·cm.
Is the data export format compatible with LIMS systems?

CSV exports contain tab-delimited columns with ISO 8601 timestamps, parameter units, and metadata fields—structured for direct ingestion into common LIMS platforms without transformation.
Does the device support multi-user access control?

Firmware v2.3+ introduces role-based login (Admin/Operator/Viewer) with password-protected calibration and data deletion functions—supporting GLP audit readiness.
How long does a full charge last under typical usage?

Approximately 100 hours of continuous operation or >1200 single measurements per charge, based on ambient temperature (25 °C) and default backlight settings.