Leici DZS-708T Multi-Parameter Water Quality Analyzer

Overview

The Leici DZS-708T Multi-Parameter Water Quality Analyzer is a laboratory-grade, modular electrochemical platform engineered for precise, traceable, and regulatory-compliant analysis of potable water, wastewater, environmental surface water, and process streams. It integrates three independent measurement modules—pH/pX (ion-selective electrode), conductivity (four-electrode or two-electrode mode), and polarographic dissolved oxygen—within a single, unified instrument architecture. The system operates on potentiometric, conductimetric, and amperometric principles respectively, enabling simultaneous or sequential quantification of critical water quality indicators per ISO 5667-3, ASTM D1293 (pH), ASTM D5391 (conductivity), and ISO 5814 (DO). Designed for routine QC/QA laboratories in municipal utilities, environmental testing facilities, food & beverage production, and pharmaceutical water systems, the DZS-708T meets functional requirements for method validation, calibration traceability, and long-term stability monitoring under controlled ambient conditions (15–30 °C, ≤80% RH).

Key Features

• High-resolution 7-inch color TFT touchscreen with intuitive icon-driven UI supporting English and Chinese language selection and dual temperature units (°C/°F)
• IP54-rated enclosure for dust resistance and limited splash protection during benchtop operation
• Integrated electrode diagnostics: real-time impedance monitoring, slope assessment, and asymmetry potential evaluation for pH and ISE electrodes
• Auto-endpoint detection with configurable criteria: stable-slope, time-based, or user-defined tolerance (±0.002 pH / ±0.1 mV over 10 s)
• Multi-point calibration support: up to 6-point pH/ISE calibration; 1-point ORP; 1–5-point conductivity; zero/full-scale DO calibration with manual or automatic atmospheric pressure compensation (kPa, mbar, Torr, atm)
• Comprehensive temperature compensation: linear/non-linear conductivity models; salinity-adjusted DO compensation; selectable reference temperatures (5.0–25.0 °C); automatic NTC/PT100 sensor recognition
• Firmware-upgradable architecture enabling future protocol expansion (e.g., new ion modes, compliance modules, or LIMS interface enhancements)

Sample Compatibility & Compliance

The DZS-708T accommodates standard laboratory sample formats including 10–100 mL beakers, 50 mL centrifuge tubes, and flow-through cells (with optional adapter). It supports aqueous matrices across wide ionic strength ranges—from ultrapure water (resistivity up to 100.0 MΩ·cm) to high-salinity brines (up to 8.00% salinity). Electrode compatibility includes tri-combined pH electrodes (with integrated temperature sensor), graphite or platinum conductivity cells (cell constants 0.01–10.0 cm⁻¹), and Clark-type polarographic DO probes. Regulatory alignment includes full GLP data integrity features: unique user IDs with role-based access (Admin/Operator/Reviewer), mandatory electronic signatures for critical actions (calibration, method change, data export), timestamped audit logs retained for ≥12 months, and immutable raw data storage. When paired with Leici’s certified communication software, the system satisfies FDA 21 CFR Part 11 requirements for electronic records and signatures—including operator authentication, event logging, and record retention controls.

Software & Data Management

Data handling conforms to ISO/IEC 17025 Clause 7.5.2 for result reporting integrity. The instrument stores ≥1000 complete measurement records locally, each containing metadata: sample ID, operator, date/time, electrode serial numbers, calibration history, environmental conditions (temp, pressure), and raw sensor outputs. Retrieval supports filtering by parameter, date range, or operator; display options include tabular listing or time-series trend plots (pH vs. time, DO decay curves). Export formats include CSV (for Excel/LabChart), PDF (print-ready reports with header/footer customization), and XML (LIMS-compatible schema). USB host port enables direct transfer to flash drives; RS-232 supports legacy thermal printers (user-selectable report templates); USB-C connection enables bidirectional synchronization with PC-based Leici LabManager software—enabling batch statistical analysis (mean, SD, RSD, confidence intervals), calibration curve regression (linear, polynomial, Gran plot), and automated compliance reporting (e.g., USP conductivity pass/fail flags).

Applications

• Environmental monitoring: EPA Method 150.1 (conductivity), 150.2 (pH), and 360.1 (DO) compliance testing of surface water, groundwater, and effluent
• Pharmaceutical water systems: USP purified water and WFI conductivity verification; TOC correlation via resistivity trending
• Food & beverage QA: Ash content determination per AOAC 976.15 (white sugar) and AOAC 984.27 (HFCS); brine salinity control in canning operations
• Academic research: Multi-ion speciation studies (e.g., NH₄⁺/NO₃⁻ dynamics in nitrification assays); kinetic DO consumption modeling in BOD incubations
• Industrial process control: Cooling tower water chemistry (pH, conductivity, corrosion index); boiler feedwater purity screening

FAQ

Does the DZS-708T support ASTM D1125-compliant conductivity measurements for ultrapure water?
Yes—when used with a 0.01 cm⁻¹ cell and enabled pure-water compensation mode, it meets ASTM D1125 resolution and temperature correction requirements for resistivity values >1 MΩ·cm.
Can the instrument store calibration history per electrode, not just per parameter?
Yes—each electrode is assigned a unique ID; all calibrations (date, solution lot, slope, offset, R²) are logged against that ID and retrievable independently.
Is GMP-compliant audit trail functionality built-in or dependent on PC software?
Core audit trail (user logins, calibration events, data deletions) is embedded in firmware; full 21 CFR Part 11 compliance (e.g., electronic signatures, record locking) requires Leici LabManager v3.2+ and configured Windows domain authentication.
What is the maximum allowable sample temperature for DO measurement without membrane damage?
The included polarographic probe is rated for continuous operation up to 45 °C; intermittent exposure to 50 °C is permissible if duration <5 minutes and thermal shock is avoided.
How does the instrument handle low-conductivity samples below 10 μS/cm?
It automatically engages high-sensitivity circuitry and applies non-linear temperature compensation optimized for deionized water; use of a 0.01 cm⁻¹ cell is recommended for optimal signal-to-noise ratio.