HORIBA LAQUAtwin pH B-711/B-712 Pocket-Sized pH Meter
| Brand | HORIBA |
|---|---|
| Origin | Japan |
| Model | B-711 / B-712 |
| Instrument Type | Pen-style pH Meter |
| Parameter Type | Single-parameter (pH) |
| Measurement Range | 2.0–12.0 pH |
| Accuracy | ±0.1 pH |
| Resolution | 0.1 pH |
| Calibration Solutions | pH 4.01, 7.00, and 9.18 standard buffers |
| Calibration Modes | B-711 — single-point |
| Temperature Compensation | Automatic (ATC) |
| IP Rating | IP67 (dust-tight |
| Sample Volume | ≥0.05 mL (with optional sampling film) |
| Operating Environment | 5–40 °C, ≤85% RH (non-condensing) |
| Power | Two CR2032 lithium batteries |
| Dimensions (L×W×H) | 164 × 29 × 20 mm (excl. protrusions) |
| Weight | ~50 g (instrument only, excl. batteries) |
Overview
The HORIBA LAQUAtwin pH B-711 and B-712 are compact, handheld pH meters engineered for rapid, reliable field and benchtop measurements in quality control, environmental monitoring, food safety, aquaculture, hydroponics, and educational laboratories. Unlike conventional glass-electrode benchtop systems, these pen-style instruments integrate a flat-surface pH sensor based on HORIBA’s proprietary solid-state electrode technology—designed to deliver stable potential response with minimal sample volume and high mechanical robustness. The measurement principle follows the Nernst equation, where the electrode potential difference between the sensing membrane and reference system is linearly proportional to pH under controlled temperature conditions. Built-in automatic temperature compensation (ATC) ensures traceable readings across the operational range of 5–40 °C. With an IP67-rated enclosure, the device withstands incidental immersion, dust ingress, and routine handling in non-laboratory environments—making it suitable for GLP-aligned workflows where portability and durability are critical.
Key Features
- Flat-surface pH electrode enabling accurate measurement from as little as 0.05 mL sample volume (when used with optional sampling film)
- Intuitive one-button operation: simultaneous calibration and measurement initiation; visual confirmation via smiley-face icon upon stabilization
- Selectable calibration protocols—B-711 supports single-point (pH 7.00); B-712 supports either single- or two-point (pH 4.01/7.00 or 7.00/9.18) calibration per ISO 8655-5 and ASTM D1293 guidance
- Auto-hold function freezes the stabilized reading, eliminating operator-dependent timing errors
- IP67-rated housing compliant with IEC 60529:2013—tested for dust-tightness and water immersion up to 1 m for 30 minutes (not intended for underwater operation)
- Low-power design with dual CR2032 coin-cell batteries providing >10,000 measurements per set under typical usage
Sample Compatibility & Compliance
The LAQUAtwin B-711/B-712 is optimized for aqueous solutions with low turbidity and suspended solids. For samples containing particulates, use of the optional filtration membrane (HORIBA Part No. 9532-30K) is recommended prior to measurement to prevent sensor fouling and ensure reproducible junction potential. The instrument complies with general requirements for portable electrochemical sensors outlined in ISO 15197:2013 (for performance criteria), and its calibration methodology aligns with USP and EP 2.2.3 guidelines for pH measurement validation. While not FDA 21 CFR Part 11–compliant out-of-the-box (lacking electronic audit trail), the device supports manual record-keeping in GMP/GLP environments when used with controlled calibration logs and documented environmental conditions.
Software & Data Management
These models operate autonomously without PC connectivity or proprietary software. All calibration data, measurement history, and battery status are retained in non-volatile memory. Users maintain traceability through manual entry into laboratory notebooks or LIMS-compatible spreadsheets. For regulatory documentation, HORIBA provides Certificate of Conformance (CoC) and factory calibration reports upon request—each unit is individually tested against NIST-traceable buffer standards before shipment. Firmware updates are not supported; however, hardware longevity is ensured by corrosion-resistant stainless-steel sensor housing and sealed internal electronics.
Applications
- Routine pH verification in beverage production lines (e.g., soft drinks, brewing wort, dairy processing)
- In-field water quality assessment for municipal wastewater effluent, irrigation channels, and aquarium systems
- Quick-check screening during agricultural soil extract analysis and nutrient solution management in vertical farms
- Teaching labs requiring student-safe, low-maintenance instrumentation with immediate visual feedback
- Pre-screening of cleaning-in-place (CIP) rinse water in pharmaceutical manufacturing facilities
FAQ
What is the minimum sample volume required for accurate measurement?
A minimum of 0.05 mL is achievable using the optional sampling film accessory; otherwise, ≥0.1 mL is recommended for direct droplet contact.
Can the B-711 perform two-point calibration?
No—the B-711 is hardware-configured for single-point calibration only; the B-712 supports both single- and two-point modes via menu selection.
Is the device suitable for measuring viscous or high-protein samples?
Not recommended without filtration; protein adsorption or viscosity-induced diffusion lag may impair response time and accuracy. Use of the filtration membrane and frequent electrode rinsing is advised.
How often should calibration be performed?
Calibration is required before each measurement session and whenever ambient temperature shifts by >5 °C or after exposure to extreme pH values outside 5–9 range.
Does the IP67 rating permit sterilization by autoclaving?
No—autoclaving exceeds the device’s thermal and pressure specifications. Surface disinfection with 70% ethanol is permitted; avoid immersion in strong oxidizers or organic solvents.
