FangZhou DDS-307+ Benchtop Wastewater Conductivity Meter

Overview

The FangZhou DDS-307+ Benchtop Wastewater Conductivity Meter is a microprocessor-controlled, laboratory-grade electrochemical instrument engineered for precise, reproducible measurement of electrical conductivity in industrial wastewater, effluent streams, and environmental monitoring samples. Based on the fundamental principle of two-electrode AC conductivity measurement—applying a low-voltage, frequency-modulated excitation signal to minimize polarization effects—the DDS-307+ delivers stable readings across seven programmable conductivity ranges. Its design prioritizes robustness in demanding lab environments: the front panel features sealed touch-sensitive keys, and the chassis incorporates corrosion-resistant materials with an IP65-rated enclosure to withstand chemical splashes, humidity, and routine decontamination procedures. The meter supports automatic temperature compensation (ATC) using integrated Pt1000 or thermistor probes, applying a user-selectable or default 2.0%/°C linear coefficient per IEC 60746-3 and ASTM D1125 guidelines.

Key Features

• Seven-range auto-scaling conductivity measurement (0.000–0.200 μS/cm up to 20.00–200.00 mS/cm), eliminating manual range selection errors
• High-resolution A/D conversion with 0.001 μS/cm minimum resolution in ultra-low-conductivity mode (DJS-0.01 cell)
• Integrated ATC and manual temperature compensation (−5.0 to +105.0 °C), with ±0.3 °C accuracy and 0.1 °C display resolution
• Dual-input architecture supporting interchangeable conductivity cells (DJS-0.01, DJS-0.1, DJS-1.0, DJS-10.0) and external temperature sensors
• RS232 serial interface compliant with EIA/TIA-232 standards for bidirectional data logging and remote calibration verification
• ISO 9001–certified quality management system applied throughout assembly, functional testing, and final calibration traceability
• Three-year limited warranty on main unit; replacement guarantee within six months for verified manufacturing defects

Sample Compatibility & Compliance

The DDS-307+ is validated for use with aqueous wastewater matrices containing suspended solids, moderate organic load, and variable ionic strength—common in municipal treatment plants, electroplating rinse baths, and food processing effluents. When paired with the optional DJS-0.01 cell and flow-through cell adapter, it meets ASTM D5391 requirements for ultrapure water conductivity assessment (<0.1 μS/cm). All firmware and hardware comply with electromagnetic compatibility (EMC) directives per IEC 61326-1 for laboratory equipment. Calibration protocols align with ISO/IEC 17025–recommended practices for metrological traceability, and documentation supports GLP audit readiness—including calibration certificate templates and instrument logbook fields for operator signature, date, standard used (e.g., KCl 0.01 mol/L, certified reference material), and deviation records.

Software & Data Management

Data acquisition is supported via standard RS232 protocol at 9600 bps (8N1), enabling direct integration with LIMS platforms or custom Python/Excel-based acquisition scripts. The meter stores no internal memory but transmits real-time values, temperature, range ID, and timestamp (when synchronized with host PC) as ASCII strings. FangZhou provides a Windows-compatible terminal utility for manual data capture, print-to-PDF reporting, and CSV export—fully compatible with FDA 21 CFR Part 11–aligned validation packages when deployed with electronic signature modules. Audit trail functionality is host-system dependent; however, the device’s fixed firmware version (v2.1.4) and immutable serial number ensure consistent configuration control during GMP audits.

Applications

• Regulatory compliance monitoring of discharge permits (e.g., EPA NPDES limits, China’s GB 8978–1996)
• Process control in activated sludge systems, reverse osmosis pre-treatment, and ion exchange regeneration cycles
• Quality verification of reclaimed water used in cooling towers or landscape irrigation
• Educational laboratories for teaching fundamental electrochemistry, solution conductivity theory, and temperature compensation models
• Field-deployable benchtop verification where portable meters require secondary calibration checks

FAQ

What conductivity cell constants are supported?
The DDS-307+ accepts DJS-0.01, DJS-0.1, DJS-1.0, and DJS-10.0 standardized cells. Cell constant is entered manually during setup and retained across power cycles.
Is the instrument suitable for high-purity water measurement?
Yes—when used with a calibrated DJS-0.01 cell and flow-through adapter, it achieves reliable sub-1.0 μS/cm measurements per ASTM D5391 Annex A1.
Does the RS232 interface support command-driven operation?
No—the interface operates in streaming mode only; no SCPI or proprietary command set is implemented.
How is calibration traceability maintained?
Each unit ships with a factory calibration certificate referencing NIST-traceable KCl standards; users must perform interval calibrations using certified reference solutions and document results per ISO/IEC 17025 Clause 7.7.
Can temperature be measured independently of conductivity?
Yes—the instrument displays temperature continuously, even with no conductivity cell connected, provided a valid Pt1000 or thermistor probe is installed.