Leici DDSJ-308F Benchtop Conductivity Meter

Overview

The Leici DDSJ-308F Benchtop Conductivity Meter is a high-precision, multi-parameter electrochemical analyzer engineered for routine and regulatory-compliant conductivity, resistivity, total dissolved solids (TDS), salinity, and temperature measurements in analytical laboratories, water quality testing facilities, pharmaceutical QC labs, and academic research environments. Based on four-electrode or two-electrode AC conductivity measurement principles (frequency-selective excitation at 1 kHz and auto-switching to lower frequencies for low-conductivity samples), the instrument delivers stable, drift-free readings across an exceptionally wide dynamic range—from ultra-pure water (≥5.00 Ω·cm) to concentrated brines (up to 1000 mS/cm). Its integrated temperature sensor (Pt1000-class) enables real-time automatic temperature compensation (ATC) per DIN/ISO 7888 algorithms, with user-selectable β coefficients (0.0–10.0 %/°C) and manual override capability. Designed to meet the metrological requirements of Class 0.5 instruments per JJG 376–2007 (Chinese national verification regulation), it serves as a primary reference tool for calibration traceability in GLP and GMP workflows.

Key Features

• Multi-parameter measurement engine: Simultaneous acquisition and display of conductivity, resistivity, TDS (with configurable conversion factor: 0.4–1.0), salinity (based on PSS-78 practical salinity scale), and temperature—all with full cross-parameter interdependence.
• Smart electrode management: Automatic frequency switching (1 kHz / 10 kHz / 100 kHz) ensures optimal signal-to-noise ratio across all ranges; single electrode (e.g., DJS-1C platinum black or K=0.01 cm⁻¹ titanium) covers full 0.000 µS/cm–1000 mS/cm span without manual range changes.
• Three intelligent read modes: Smart-Read (user-defined stability thresholds: “Fast/Medium/Strict”); Timed-Read (programmable interval logging from 1 s to 99 h 59 min); Cont-Read (real-time trend visualization with 1 Hz sampling).
• Advanced calibration architecture: Supports up to 3-point conductivity standard calibration (preloaded NIST-traceable KCl standards: 84 µS/cm, 1413 µS/cm, 12.88 mS/cm, 111.8 mS/cm); optional TDS factor and cell constant (K) redefinition with audit trail logging.
• Robust data integrity system: 500-measurement storage per parameter (conductivity/TDS/salinity), timestamped with operator ID, electrode ID, calibration history, and environmental metadata; export via USB to CSV or direct RS-232 serial printer output.
• Human-centric interface: 128×64 dot-matrix LCD with adjustable backlight, tactile membrane keypad (PC-based housing), and intuitive Chinese/English bilingual menu navigation—optimized for gloved operation and low-light lab conditions.

Sample Compatibility & Compliance

The DDSJ-308F accommodates aqueous solutions across diverse matrices: ultrapure water (UPW), pharmaceutical buffers (e.g., WFI, Purified Water per USP ), seawater analogs, industrial process streams, wastewater effluents, and food-grade brines. Its sealed measurement cell design minimizes evaporation artifacts during extended monitoring. The instrument conforms to international standards including ISO 7888 (electrical conductivity of water), ASTM D1125 (standard test methods for electrical conductivity of water), and USP (water conductivity testing for pharmaceutical use). Full GLP compliance is enabled through mandatory electronic signatures, 21 CFR Part 11–compatible audit trails (calibration events, data edits, user logins), and password-protected configuration access levels (Operator/Supervisor/Administrator).

Software & Data Management

Data transfer and remote control are supported via standard USB 2.0 (CDC class) and RS-232 interfaces. Leici’s official LabLink Pro software (Windows-compatible) provides secure, encrypted PC synchronization, customizable report generation (PDF/Excel), statistical analysis (mean, SD, RSD, linear regression), and electronic signature workflows. All stored measurements include embedded metadata: date/time stamp, ambient temperature, electrode serial number, calibration date, and operator code. Internal non-volatile memory retains all data and settings during power loss—ensuring continuity in regulated environments where instrument downtime must be minimized.

Applications

• Pharmaceutical manufacturing: Conductivity verification of Water for Injection (WFI), Purified Water, and Clean-in-Place (CIP) rinse cycles per EU Annex 1 and FDA guidance.
• Power plant chemistry: Monitoring condensate purity, boiler feedwater resistivity (>10 MΩ·cm), and cycle chemistry control.
• Environmental laboratories: EPA Method 120.1–compliant TDS quantification and salinity profiling in estuarine and marine studies.
• Academic research: Electrolyte characterization in battery electrolyte development, corrosion inhibitor screening, and colloidal dispersion stability assessment.
• Food & beverage QA: Batch consistency checks for brining solutions, dairy processing water, and beverage concentrate dilution control.

FAQ

Does the DDSJ-308F support automatic temperature compensation for all measured parameters?
Yes—ATC is applied in real time to conductivity, resistivity, and TDS calculations using either built-in Pt1000 sensor data or external probe input; salinity uses ITS-90–based thermodynamic algorithms.
Can the instrument be calibrated with non-standard KCl solutions?
Yes—users may enter custom standard values (conductivity and temperature) during multi-point calibration, with full traceability logging.
Is firmware upgrade capability available in the field?
Yes—USB-based firmware updates are supported via Leici’s certified update utility; version history and checksum validation ensure integrity.
What electrode types are compatible with the DDSJ-308F?
Standard compatibility includes DJS-1C (platinum black, K=1.0 cm⁻¹), DJS-0.1C (K=0.1 cm⁻¹), and specialized low-conductivity cells (e.g., titanium K=0.01 cm⁻¹); all feature BNC or 6-pin DIN connectors.
How is data security enforced under 21 CFR Part 11 requirements?
Through role-based access control, electronic audit trails with immutable timestamps, operator authentication (username/password), and tamper-evident record locking—no data modification permitted without documented justification and supervisor approval.