Leici PXSJ-226T Benchtop Ion Meter

Overview

The Leici PXSJ-226T Benchtop Ion Meter is a high-precision potentiometric analyzer engineered for quantitative determination of monovalent and multivalent ions—including F⁻, Cl⁻, NO₃⁻, NH₄⁺, K⁺, Na⁺, and others—in aqueous environmental, industrial, and regulatory laboratory settings. It operates on the principle of ion-selective electrode (ISE) potentiometry, measuring the electromotive force (EMF) generated at the interface between an ion-selective membrane and the sample solution. This EMF is logarithmically related to the activity (and thus concentration) of the target ion, per the Nernst equation. Designed for rigorous water quality analysis workflows—especially in municipal drinking water monitoring, wastewater treatment compliance, soil leachate testing, and pharmaceutical excipient purity verification—the PXSJ-226T integrates electrochemical accuracy with robust firmware architecture and traceable data governance.

Key Features

• High-resolution color LCD touchscreen with intuitive icon-based navigation and dual-language support (English/Chinese)
• Selectable resolution modes: pX up to 0.001 pX; mV up to 0.01 mV; temperature to 0.1 °C/°F
• Multi-parameter calibration suite: 1–6 point pH/ion electrode calibration with built-in diagnostic routines; 1-point ORP calibration; automatic slope and offset validation
• Intelligent endpoint detection: supports auto-read, timed-read, interval-read, and manual read modes with configurable stability criteria
• Comprehensive temperature compensation: automatic or manual input; selectable units (°C/°F); external Pt1000 or integrated sensor compatibility
• IP54-rated enclosure for dust resistance and limited water splashing protection in shared lab environments
• Firmware-upgradable platform enabling method expansion, protocol customization, and future regulatory alignment (e.g., updated USP or ISO 17025 metadata requirements)

Sample Compatibility & Compliance

The PXSJ-226T accepts standard 12-mm diameter ion-selective electrodes and combination pH/ISE probes, including solid-state, liquid-membrane, and crystal-membrane configurations (e.g., LaF₃ for fluoride). It accommodates samples with turbidity up to 500 NTU and total dissolved solids (TDS) ≤ 200,000 mg/L, provided appropriate ionic strength adjustment (e.g., TISAB addition for F⁻ analysis) is applied. The instrument conforms to international metrological standards for electrochemical instrumentation, including IEC 61000-4 (EMC immunity), ISO/IEC 17025:2017 clause 6.4.7 (equipment suitability), and ASTM D1129 (standard terminology relating to water). Its embedded GLP/GMP framework enforces user authentication, role-based access control (administrator/operator/analyst), full audit trails (including calibration edits, data deletions, and method changes), and electronic signature readiness per FDA 21 CFR Part 11 Annex 11 requirements.

Software & Data Management

Data integrity is enforced through a secure local database storing up to 1000 complete measurement records—including sample ID, electrode serial number, calibration curve coefficients, temperature, date/time stamp, operator ID, and raw mV/pX values. All entries are immutable post-acquisition unless authorized via multi-level password protection. USB and RS-232 interfaces enable bidirectional communication with LIMS (e.g., LabWare, Thermo SampleManager) and validated PC software for advanced statistical analysis (RSD%, confidence intervals, trend charts). U disk support allows encrypted export of CSV or PDF reports compliant with ISO/IEC 17025 documentation clauses. Optional barcode scanning integration streamlines sample ID entry and reduces transcription errors during high-throughput batch analysis.

Applications

• Environmental monitoring: Fluoride quantification in groundwater per WHO Guideline Limits (1.5 mg/L) and EPA Method 300.0
• Wastewater discharge compliance: Chloride and ammonium ion profiling against EU Urban Wastewater Treatment Directive limits
• Pharmaceutical water systems: Conductivity-corrected Na⁺ and Cl⁻ monitoring in Purified Water (PW) and Water for Injection (WFI) per USP
• Food safety laboratories: Nitrate/nitrite screening in vegetable extracts using standard addition methodology
• Academic research: Multi-ion speciation studies in hydroponic nutrient solutions and simulated acid rain experiments

FAQ

Does the PXSJ-226T support automatic temperature compensation for all ion measurements?

Yes—it applies Nernstian temperature correction across all supported ion modes using either internal thermistor or external Pt1000 probe input.
Can calibration data be exported for external audit review?

Absolutely. Calibration logs—including standard concentrations, measured mV, slope (%), offset (mV), R² value, and operator ID—are exportable in timestamped CSV format via USB.
Is the instrument compatible with third-party ISEs from Thermo Orion or Metrohm?

It accepts any BNC-terminated ISE meeting standard output impedance (<100 MΩ) and voltage range (±1800 mV), though Leici-certified electrodes ensure optimal slope stability and drift performance.
How does the GRAN plot method function within this platform?

The built-in GRAN algorithm performs linear regression on transformed titration data (V·10^E/S vs. V), automatically calculating equivalence point and ion concentration without manual graphing—fully compliant with ISO 9964-1 for fluoride determination.
What cybersecurity measures are implemented for network-connected operation?

While the PXSJ-226T lacks native Ethernet/WiFi, its RS-232 and USB interfaces operate in isolated serial mode; when connected to validated IT infrastructure, it inherits host-level firewall, encryption, and endpoint protection policies per NIST SP 800-53 Rev. 5.