HORIBA LAQUAact D-73 Portable pH/ORP/Ion Meter

Overview

The HORIBA LAQUAact D-73 is a rugged, field-deployable handheld meter engineered for high-reliability multi-parameter water quality analysis in demanding environmental, industrial, and regulatory settings. Based on potentiometric measurement principles—employing glass pH electrodes, platinum or Ag/AgCl ORP sensors, and ion-selective electrodes (ISEs)—the D-73 delivers stable, traceable readings across pH (0.00–14.00), ORP (±2000 mV), and monovalent/divalent ion concentrations (e.g., Na⁺, K⁺, Ca²⁺, F⁻, Cl⁻) with selectable units (ppm, mg/L, mol/L, pX). Its dual-channel display simultaneously presents two real-time parameters—such as pH + temperature or mV + ion activity—enabling rapid cross-correlation without mode switching. Designed for continuity between lab bench and field site, the D-73 maintains metrological integrity under variable ambient conditions, including low-light or high-humidity environments.

Key Features

• Rugged polycarbonate housing rated IP67—submersible to 1 m for 30 minutes; resistant to impact, solvents (including 70% ethanol), weak acids/bases, and oils.
• Dual-parameter backlit LCD display—1.4× larger than predecessor models—with simultaneous readout of primary and secondary measurements (e.g., pH + conductivity, ORP + temperature).
• Ergonomic single-hand operation: three dedicated function keys simplify calibration, measurement, and data recall; optimized grip geometry reduces operator fatigue during extended field surveys.
• Rotating adjustable electrode stand enables precise, tool-free positioning for benchtop use; integrated electrode hook secures cables and sensors during transport.
• Extended battery life—up to 1,000 hours on standard alkaline cells—minimizes downtime in remote monitoring applications.
• GLP/GMP-compliant data management: internal memory stores 1,000 timestamped, operator-ID-tagged records with calibration history; exportable via USB interface using HORIBA’s free LAQUA software (requires registered account).

Sample Compatibility & Compliance

The D-73 supports a wide range of aqueous samples—from freshwater streams and wastewater effluents to industrial process waters and purified laboratory-grade solutions. It accommodates standard BNC- and DIN-compatible pH, ORP, ISE, and conductivity electrodes (conductivity functionality requires optional EC sensor module or compatible probe). All measurements adhere to internationally recognized electrochemical standards—including ASTM D1293 (pH of water), ISO 7888 (electrical conductivity), and ISO 11276 (soil solution pH)—and support audit-ready documentation per FDA 21 CFR Part 11 when paired with validated printer and software configurations. The instrument’s calibration verification routines include slope and offset diagnostics for pH/ISE, and millivolt stability checks for ORP—ensuring traceability to NIST-traceable reference buffers.

Software & Data Management

Data acquisition and reporting are managed through HORIBA’s LAQUA software suite—freely downloadable after user registration. The software enables batch import/export of measurement logs, calibration certificate generation, trend visualization, and customizable report templates compliant with ISO/IEC 17025 and EPA method requirements. All stored data include metadata: date/time stamp, electrode ID, calibration status, temperature compensation mode (ATC/MTC), and user-defined sample IDs. Audit trails record every calibration event, parameter change, and data export action—meeting GLP/GMP electronic record retention mandates. Printer output (via optional thermal printer) includes full calibration summary, measurement uncertainty indicators, and signature fields for QA sign-off.

Applications

• Environmental monitoring: Surface water, groundwater, and effluent compliance testing per EPA, EU WFD, or local discharge regulations.
• Drinking water treatment: Real-time pH and disinfectant residual (via ORP) control at intake, filtration, and distribution points.
• Aquaculture & hydroponics: Daily tracking of ion balance (e.g., K⁺, Ca²⁺) and redox potential to optimize nutrient uptake and pathogen suppression.
• Industrial process control: Boiler feedwater conditioning, electroplating bath monitoring, and chemical dosing verification.
• Educational laboratories: Multi-parameter experiments illustrating acid-base equilibria, ion activity coefficients, and Nernst equation behavior.

FAQ

Does the D-73 measure conductivity natively?
The D-73 supports conductivity measurement only when equipped with a compatible EC probe and activated via firmware configuration; it is not included as a default parameter in base models.
Can the D-73 store calibration data alongside measurements?
Yes—each stored measurement record retains associated calibration information (buffer values, slope, offset, date/time), enabling full traceability per ISO/IEC 17025 Clause 7.7.
Is the instrument suitable for saline or seawater analysis?
With appropriate high-salinity pH and ORP electrodes (e.g., double-junction, gel-filled), the D-73 performs reliably in brackish and marine environments up to 50 ppt salinity.
What battery type does the D-73 use, and is battery replacement field-serviceable?
It operates on four standard AA alkaline batteries; the compartment is user-accessible without tools and sealed to maintain IP67 integrity post-replacement.
Does the D-73 meet FDA 21 CFR Part 11 requirements out-of-the-box?
Full Part 11 compliance requires configuration with password-protected user roles, electronic signatures, and audit-trail-enabled software—achievable via LAQUA software v3.2+ and validated printer integration.