HORIBA LAQUAtwin B-711/B-712 Portable Pocket pH Meter

Overview

The HORIBA LAQUAtwin B-711 and B-712 are compact, handheld pocket pH meters engineered for rapid, reliable field and laboratory measurements in demanding environments. Based on proven glass electrode potentiometry—compliant with ISO 3696, ASTM D1293, and USP principles—the instruments deliver high reproducibility and stability across aqueous samples with minimal sample consumption. Unlike conventional benchtop or probe-based systems, the B-711/B-712 integrate a proprietary flat-surface pH electrode architecture developed through decades of HORIBA electrochemical sensor R&D. This design enables stable potential generation from as little as 0.05 mL of sample when used with the optional sampling film accessory—ideal for micro-volume applications including plant sap analysis, food surface testing, pharmaceutical formulation checks, and environmental water screening. The devices feature an integrated temperature sensor for automatic temperature compensation (ATC) across the full operating range (5–40 °C), eliminating manual correction and reducing operator-induced error.

Key Features

• Ultra-low sample requirement: Measures accurately with ≥0.05 mL (using LAQUAtwin Sampling Film B) or ≥0.1 mL (standard mode), minimizing waste and enabling analysis where sample volume is critically limited
• Intuitive one-touch operation: Single-button activation for both calibration and measurement; visual confirmation via smiley-face icon on LCD display ensures correct measurement completion
• Ruggedized industrial design: IP67-rated enclosure provides full dust ingress protection and submersion resistance to 1 m for 30 minutes—validated per IEC 60529—making it suitable for outdoor, agricultural, and industrial hygiene use
• Optimized electrode geometry: Flat-surface glass electrode eliminates air bubble entrapment and improves response time (<10 seconds typical stabilization), especially in viscous or particulate-laden samples (when used with optional filter membrane)
• Battery-efficient architecture: Dual CR2032 cells support >5,000 measurements per set under typical usage; low-power LCD with backlight-free contrast ensures readability in direct sunlight
• Calibration flexibility: B-711 supports single-point calibration (typically at pH 7.00); B-712 offers user-selectable one- or two-point calibration (pH 4.01/7.00 or 7.00/9.18), enhancing traceability and linearity verification per GLP requirements

Sample Compatibility & Compliance

The LAQUAtwin B-711/B-712 is validated for use with clear to mildly turbid aqueous solutions, including drinking water, wastewater effluent, nutrient solutions, fermentation broths, fruit juices, dairy products, and cosmetic emulsions. For samples containing suspended solids or fibers, HORIBA recommends pairing the instrument with its certified filter membrane (LAQUAtwin Filter Membrane Kit) to prevent electrode fouling and ensure Nernstian response. The system complies with international electrochemical measurement standards—including ISO 10523 (water quality – pH determination), ASTM E70 (standard test method for pH of aqueous solutions), and JP/EP/USP general chapters on pH measurement—and supports audit-ready documentation when operated within defined calibration and handling protocols. While not designed for continuous immersion or high-pressure sterilization, its IP67 rating meets common field-deployment requirements under FDA 21 CFR Part 11-aligned workflows when paired with secure logbook practices.

Software & Data Management

As a standalone portable meter, the B-711/B-712 does not interface directly with PC software or cloud platforms. However, all measurement data—including date/time stamp, measured pH value, temperature reading, and calibration status—is retained in non-volatile memory for up to 100 records. Data export is performed manually via visual transcription or photography, consistent with lean QC practices in regulated environments where electronic record integrity must be controlled per ALCOA+ principles. The auto-hold function freezes stable readings automatically, supporting GMP-compliant manual entry into ELN or paper-based batch records. Firmware updates are not field-upgradable; units ship with factory-verified calibration and firmware revision traceability documented in the Certificate of Conformance supplied with each device.

Applications

• Agricultural field testing: Sap pH of hydroponic crops, soil extract analysis, fertilizer solution monitoring
• Food & beverage QA/QC: Surface pH of meat, cheese rinds, baked goods; pH profiling during fermentation and pasteurization validation
• Environmental monitoring: On-site pH assessment of rivers, lakes, stormwater runoff, and leachate without sample transport delays
• Pharmaceutical manufacturing: In-process checks of buffer solutions, cleaning agent residuals, and final rinse water compliance (e.g., WFI rinse validation per EU Annex 1)
• Education & training: Robust platform for undergraduate chemistry labs emphasizing electrode theory, calibration hierarchy, and measurement uncertainty fundamentals
• Swimming pool & spa maintenance: Rapid verification of disinfectant efficacy via pH correlation with free chlorine stability

FAQ

What is the minimum sample volume required for accurate measurement?
With the optional LAQUAtwin Sampling Film B, the B-711/B-712 achieves stable readings from as little as 0.05 mL. Without the film, ≥0.1 mL is required. Always close the light-shielding cap during measurement to ensure optical and thermal stability.
Can the B-711/B-712 measure outside the 2.0–12.0 pH range?
No. The electrode’s Nernst response and internal reference system are optimized and validated exclusively for pH 2.0–12.0. Measurements beyond this range risk nonlinearity, slow response, and accelerated electrode aging.
Is the instrument compliant with FDA 21 CFR Part 11 for electronic records?
The device itself does not generate electronic records; it displays and stores values locally without network connectivity or digital signature capability. Its use in Part 11 environments requires procedural controls—such as defined calibration logs, operator training records, and manual transcription SOPs—to maintain data integrity.
How often should the electrode be cleaned and stored?
Rinse thoroughly with deionized water after each use. Store immersed in 3 M KCl storage solution (not distilled water) to maintain junction potential and glass hydration. Clean with mild detergent or 0.1 M HNO₃ if contamination is suspected; avoid abrasive pads or organic solvents.
Does IP67 certification permit underwater operation?
No. IP67 confirms resistance to temporary submersion (1 m, 30 min), but the instrument is not rated for active measurement underwater. Operation must occur above liquid level with proper electrode wetting and cap removal prior to use.