Leici PHSJ-5T Advanced Benchtop pH/Orp Meter

Overview

The Leici PHSJ-5T is a high-precision benchtop pH and ORP meter engineered for rigorous laboratory environments where regulatory compliance, measurement reproducibility, and operational traceability are critical. Built upon a dual-sensor electrochemical platform, it measures hydrogen ion activity via potentiometric detection using glass membrane pH electrodes and redox potential via platinum or Ag/AgCl reference electrodes. Its architecture integrates analog signal conditioning with 24-bit ADC resolution, enabling stable baseline readings across the full −2.00 to 20.00 pH range—critical for applications involving highly alkaline caustic solutions, low-pH acid digestion matrices, or non-aqueous solvent systems. The instrument operates under automatic temperature compensation (ATC), utilizing either integrated Pt1000 thermistors or external temperature probes, ensuring Nernstian slope correction per ISO 3696 and ASTM D1293 standards.

Key Features

• High-resolution 7-inch color TFT touchscreen with intuitive icon-driven UI supporting both English and Chinese language modes
• Selectable measurement resolution: 0.001 / 0.01 / 0.1 pH and 0.01 / 0.1 / 1 mV for flexible calibration and reporting granularity
• Multi-standard buffer recognition: auto-identifies GB, DIN, NIST, USA, MERK, and JIS pH standards; supports user-defined buffer sets and custom calibration curves
• Comprehensive electrode diagnostics: real-time monitoring of asymmetry potential, slope deviation (%), and response time to flag aging or fouled electrodes
• Smart endpoint detection: configurable auto-read modes—including timed intervals (1–300 s), fixed-duration stabilization, and manual trigger—with programmable acceptance criteria
• Robust environmental protection: IP54-rated enclosure suitable for wet-lab benches and shared QC environments with splash exposure
• Firmware-upgradable architecture enabling future protocol expansion, including enhanced I/O mapping and LIMS integration modules

Sample Compatibility & Compliance

The PHSJ-5T accommodates standard BNC-terminated pH and ORP electrodes, including double-junction, gel-filled, and refillable configurations. It supports routine calibration from 1- to 6-point pH protocols and single-point ORP verification against Zobell’s or quinhydrone standards. All measurements adhere to GLP documentation requirements: each dataset includes timestamp, operator ID, electrode serial number, calibration history, ambient temperature, and environmental humidity (when paired with optional sensor module). Audit trails comply with FDA 21 CFR Part 11 when used with validated Leici LabLink software—supporting electronic signatures, role-based access control (three-tier user hierarchy), and immutable record retention. Instrument self-tests verify electrode impedance, reference junction integrity, and internal voltage reference stability prior to measurement initiation.

Software & Data Management

Data export and system integration occur via three hardware interfaces: RS-232 (for direct thermal printer output with customizable report templates), USB 2.0 (for PC synchronization using Leici DataMaster v3.x), and host-mode USB (for U-disk file transfer and barcode scanner input). The embedded database stores up to 1000 complete measurement records—including raw mV, calculated pH, temperature, electrode status, and calibration metadata—with searchable filters by date range, operator, or sample ID. Export formats include CSV, PDF, and XML, compatible with enterprise LIMS platforms such as Thermo Fisher SampleManager and LabWare LIMS. Optional GMP audit log module provides chronological event tracking for all configuration changes, calibrations, and data deletions—fully aligned with Annex 11 and EU GMP Chapter 4 requirements.

Applications

The PHSJ-5T serves core quality control functions in pharmaceutical manufacturing (e.g., USP pH verification of injectables and buffers), food & beverage process validation (ISO 5725-2 precision testing of dairy titratable acidity), environmental water analysis (EPA Method 150.1 for wastewater effluent pH), and academic research requiring traceable electrochemical characterization of nanomaterial dispersions or enzyme-catalyzed reaction media. Its extended pH range enables reliable monitoring of semiconductor cleaning baths (RCA SC-1/SC-2), battery electrolyte formulations, and geothermal fluid sampling—where conventional meters fail near pH 14 due to alkaline error.

FAQ

Does the PHSJ-5T support automated calibration verification using standard buffer solutions?

Yes—it performs scheduled or on-demand buffer verification against stored reference values and logs deviations exceeding user-defined thresholds.
Can the instrument be integrated into an existing 21 CFR Part 11–compliant laboratory information system?

When deployed with Leici LabLink Validation Pack and configured with digital certificate authentication, it meets electronic record and signature requirements for regulated environments.
What electrode maintenance alerts are available?

Real-time warnings include high impedance (>500 MΩ), slope drift >5% from nominal, slow response (>60 s to 95% stabilization), and junction clogging indicators.
Is temperature unit switching limited to Celsius and Fahrenheit only?

Yes—only °C and °F are supported; Kelvin conversion is not implemented due to absence of absolute zero relevance in routine pH metrology.
How does the system handle power interruption during data acquisition?

Built-in non-volatile memory preserves active measurement state and unsaved data; recovery resumes automatically upon reboot without loss of context or calibration integrity.