Leici PHB-5 Portable pH Meter

Overview

The Leici PHB-5 Portable pH Meter is a compact, field-deployable electrochemical instrument engineered for high-reproducibility pH measurement in diverse operational environments—from routine quality control in pharmaceutical water systems to environmental monitoring of surface waters and wastewater effluents. It operates on the fundamental principle of potentiometric measurement: detecting the potential difference across a glass pH electrode and reference electrode pair immersed in an aqueous sample, converting this voltage into a calibrated pH value via the Nernst equation. Designed to meet the functional expectations of laboratory technicians, field analysts, and regulatory compliance officers, the PHB-5 delivers stable readings under variable ambient conditions while maintaining traceability to national metrological standards (GB/T 23776–2018 for pH meter verification). Its lightweight form factor (≤250 g), IP65-rated enclosure, and dual-power architecture ensure uninterrupted operation during extended outdoor campaigns or mobile lab deployments.

Key Features

• High-contrast LCD display with backlight—enables legible data visualization under low-light field conditions and reduces operator eye fatigue during prolonged use.
• Intelligent self-diagnostic startup sequence—verifies electrode connection integrity, battery status, and sensor signal stability before initiating measurement, minimizing false-start errors.
• Dual temperature compensation modes—supports both automatic temperature compensation (ATC) using integrated Pt1000 sensor input and manual TC entry, ensuring accurate pH values across 0–50 °C sample ranges.
• Two-point calibration protocol with auto-buffer recognition—automatically identifies GB-specified calibration buffers (pH 4.00, 6.86, 9.18) by measured mV slope and offset, reducing human error in field calibrations; also permits manual buffer assignment for non-standard or custom reference solutions.
• Flexible reading modes—offers continuous real-time display (update rate: 1 Hz) and equilibrium-based measurement (auto-hold triggered when drift ≤0.01 pH/10 s), optimizing workflow efficiency in both rapid screening and precision verification tasks.
• Robust power architecture—integrates a rechargeable lithium-ion battery (rated for ≥12 h continuous operation) with universal AC adapter compatibility (100–240 VAC, 50/60 Hz), eliminating dependency on disposable cells and supporting GLP-compliant charging logs.

Sample Compatibility & Compliance

The PHB-5 is validated for use with aqueous liquid samples exhibiting conductivity ≥10 µS/cm and total dissolved solids (TDS) < 10,000 ppm. It accommodates standard combination pH electrodes (BNC connector, 3.5 mm pin) with glass membrane thickness optimized for low-ionic-strength samples (e.g., deionized water, rainwater, purified process streams). The instrument conforms to GB/T 11165–2022 (General Technical Requirements for pH Meters) and supports audit-ready documentation practices aligned with ISO/IEC 17025:2017 Clause 6.4.1 (Equipment Management) and USP (pH Measurement). While not inherently 21 CFR Part 11 compliant, its firmware architecture enables secure calibration logging and timestamped measurement records when paired with Leici’s optional PC-based data management software (v2.1+).

Software & Data Management

Data export is supported via USB-C interface to Windows-compatible hosts running Leici’s proprietary LeiciLab Suite v2.1. This desktop application provides encrypted storage of calibration histories (including slope %, offset mV, and buffer IDs), measurement logs with GPS-tagged metadata (when connected to external GNSS modules), and customizable report templates compliant with internal QA templates or client-specific LIMS ingestion formats (CSV, XLSX). All firmware updates are digitally signed and delivered through authenticated channels to prevent unauthorized modification—a critical requirement for laboratories operating under GMP or GLP frameworks.

Applications

• Environmental field testing: Monitoring pH stability in freshwater ecosystems, soil leachates, and municipal wastewater influent/effluent streams per EPA Method 150.1.
• Pharmaceutical manufacturing: Conducting in-process checks of purified water (PW) and water-for-injection (WFI) systems per USP and EU Annex 1 requirements.
• Food & beverage QC: Verifying acidification endpoints during fermentation, brining, and sauce formulation where batch-to-batch consistency is governed by HACCP critical limits.
• Educational laboratories: Serving as a pedagogical tool for teaching electrochemical fundamentals, calibration theory, and uncertainty propagation in undergraduate analytical chemistry curricula.
• Industrial cooling water management: Tracking alkalinity-driven pH shifts in closed-loop HVAC systems to preempt corrosion or scale formation per ASTM D3693.

FAQ

Does the PHB-5 support GLP-compliant calibration record generation?
Yes—when used with LeiciLab Suite v2.1 and a connected PC, it generates time-stamped, user-identified calibration reports including electrode ID, buffer lot numbers, slope/offset values, and pass/fail status against defined acceptance criteria.
Can the instrument be used for non-aqueous or high-viscosity samples?
No—it is validated exclusively for aqueous solutions. Non-aqueous solvents, oils, or slurries may damage the glass membrane or yield erroneous potentials due to junction potential instability.
Is electrode storage solution included with purchase?
No—electrode storage and cleaning solutions (e.g., 3 mol/L KCl, pH 4.00 buffer) must be procured separately as consumables; Leici recommends using certified reference materials traceable to NIM (National Institute of Metrology, China).
What is the recommended recalibration frequency for routine use?
Per ISO 7870-2:2021, recalibration is required before each measurement session, after electrode replacement, following exposure to extreme pH (12), or when drift exceeds ±0.02 pH between measurements.
Does the PHB-5 meet international shipping certifications?
Yes—the device complies with UN 38.3 for lithium battery transport and carries CE marking (EMC Directive 2014/30/EU and RoHS Directive 2011/65/EU), facilitating customs clearance in EU, UK, and ASEAN markets.