HORIBA LAQUAact D-70 Series Portable Multi-Parameter Water Quality Analyzer

Overview

The HORIBA LAQUAact D-70 Series is a rugged, field-deployable multi-parameter water quality analyzer engineered for high-reliability environmental monitoring, wastewater treatment verification, aquaculture management, and regulatory compliance testing. Built upon HORIBA’s decades of electrochemical sensor expertise, the D-70 employs standardized potentiometric (glass electrode), galvanic cell (membrane-covered DO), and conductometric (AC two-electrode) measurement principles—each traceable to internationally recognized reference standards including NIST, USA, and JIS-certified buffer solutions. Its dual-channel architecture enables simultaneous real-time acquisition and display of two independent parameters—e.g., pH and dissolved oxygen—without cross-interference, supporting rapid decision-making in dynamic sampling environments. Designed for GLP/GMP-aligned workflows, the instrument features built-in calibration traceability, automatic temperature compensation (0–45 °C), pressure and salinity correction for DO, and full audit-ready data logging.

Key Features

• Rugged IP67-rated housing with alcohol-resistant, impact-tolerant polymer casing—certified for immersion up to 1 m for 30 min and dust-tight operation.
• Capacitive touch-responsive monochrome LCD with adjustable backlight—optimized for readability under direct sunlight or low-light field conditions.
• Intelligent guided navigation system with on-screen troubleshooting prompts, maintenance checklists, and step-by-step calibration assistance.
• Electrode health diagnostics: real-time response kinetics visualization, post-calibration status confirmation, and automatic electrode degradation alerts.
• Dual-parameter concurrent measurement and display (e.g., pH/mV, conductivity/TDS, DO/saturation %) with independent channel configuration.
• Auto-ranging conductivity measurement (0.0 μS/m to 200.0 S/m) with automatic temperature compensation to 25 °C and selectable unit conversion (SI vs. legacy units).
• Five-point pH calibration with auto-buffer recognition (NIST/USA standards), scheduled calibration reminders, and clock-synchronized log timestamps.
• Galvanic DO sensor with integrated temperature, atmospheric pressure, and salinity compensation—ensuring accuracy across freshwater, estuarine, and brackish applications.

Sample Compatibility & Compliance

The D-70 series is validated for use with natural waters (rivers, lakes, groundwater), effluents, drinking water, seawater (up to 40 ppt), aquaculture ponds, and industrial process streams. All electrochemical sensors comply with JIS Z 8401 (pH), JIS K 0101 (conductivity/resistivity), and ASTM D1293 (pH of water). Conductivity and resistivity measurements adhere to ISO 7888 and ASTM D1125; dissolved oxygen determinations meet ASTM D888 and USP . When paired with HORIBA’s certified calibration standards and used with documented procedures, the system supports data integrity requirements under ISO/IEC 17025, EPA Method 150.1, and EU Directive 2000/60/EC (Water Framework Directive). Full GLP/GMP functionality—including electronic signatures, user access control, and 21 CFR Part 11-compliant audit trails—is enabled via HORIBA’s LAQUA Software Suite (optional).

Software & Data Management

Data from the D-70 are stored internally (1,000 records) with embedded metadata: date/time stamp, operator ID, sample ID, electrode serial numbers, calibration history, and environmental conditions (temperature, pressure, salinity). USB-C connectivity enables direct transfer to Windows-based PCs running HORIBA LAQUA Software v4.x, which provides automated report generation (PDF/CSV), trend analysis, statistical summary (mean, SD, CV%), and compliance-ready export formats aligned with LIMS integration protocols. The software enforces role-based access, version-controlled method templates, and immutable audit logs—including all calibration events, parameter changes, and data exports—satisfying FDA 21 CFR Part 11 and EU Annex 11 requirements when configured with digital signature modules.

Applications

• Field-based ambient water quality surveillance per national monitoring programs (e.g., USGS NWIS, Environment Agency UK, JMA Japan).
• Wastewater treatment plant (WWTP) influent/effluent QA/QC—verifying pH neutrality, conductivity thresholds, and DO levels prior to discharge.
• Aquaculture site management—tracking diurnal DO fluctuations, pH stability, and salinity gradients to optimize stocking density and feeding cycles.
• Drinking water distribution network validation—monitoring residual disinfectant compatibility (via ORP), corrosion potential (pH/mV), and mineral content (TDS/conductivity).
• Educational and research fieldwork—supporting undergraduate hydrology labs and graduate-level limnology studies with traceable, portable instrumentation.
• Emergency response deployments—rapid assessment of floodwater contamination, post-spill pH shifts, or algal bloom-related hypoxia events.

FAQ

What calibration standards are supported for pH measurement?
The D-70 automatically recognizes five standard buffers (1.68, 4.01, 6.86, 7.00, 9.18, 10.01, and 12.45 pH at 25 °C) compliant with both NIST and USA specifications. Calibration can be performed in any sequence, and the instrument stores full calibration history with date/time stamps.
Does the D-70 require annual recalibration or certification?
While no mandatory annual recalibration is required, HORIBA recommends biannual verification using traceable standards. For regulated environments, users must establish internal SOPs aligned with ISO/IEC 17025 or local metrological authority guidelines—typically involving quarterly performance checks and documented evidence of measurement uncertainty.
Can the D-70 measure ammonia or nitrate directly?
No—the D-70 does not include ion-selective electrodes for NH₄⁺ or NO₃⁻ out-of-the-box. However, it supports optional ISE modules (e.g., HORIBA 9619-10D NH₄⁺ electrode) via its universal analog input port, enabling quantitative ion analysis with appropriate calibration.
Is the DO sensor replaceable in the field?
Yes—the galvanic DO probe (model D-75 or OM-71) features a user-replaceable membrane cap and electrolyte cartridge. HORIBA supplies OEM replacement kits with pre-filled electrolyte and calibrated membranes, ensuring consistent performance without factory service intervention.
How is data integrity ensured during battery replacement?
All measurement data and calibration records are retained in non-volatile memory. The D-70 maintains clock synchronization for up to 72 hours after power loss, and no data are erased during battery swap—provided the replacement occurs within this window.