METTLER TOLEDO FE28-Meter Portable Multi-Parameter Benchtop Meter (pH / Conductivity / Dissolved Oxygen)

Overview

The METTLER TOLEDO FE28-Meter is a rigorously engineered portable multi-parameter benchtop meter designed for routine electrochemical analysis in quality control laboratories, field-based environmental monitoring, educational settings, and industrial process support. It integrates three core measurement modalities—pH, conductivity, and dissolved oxygen—into a single compact platform, enabling consistent, traceable measurements across diverse aqueous sample matrices. The instrument operates on potentiometric (pH), conductometric (conductivity), and amperometric (dissolved oxygen) principles, with each mode calibrated independently using NIST-traceable standards. Its robust housing, IP67-rated enclosure when equipped with appropriate probes, and low-power design support both benchtop stability and handheld mobility without compromising metrological integrity. Unlike dedicated single-mode meters, the FE28-Meter maintains independent sensor excitation circuits and signal conditioning pathways to prevent cross-modal interference—ensuring that conductivity readings remain unaffected by pH electrode polarization or DO membrane response lag.

Key Features

• Triple-parameter capability: Simultaneous configuration for pH, conductivity, and dissolved oxygen measurements with mode-specific calibration workflows.
• High-fidelity pH sensing: Supports combination electrodes with Ag/AgCl reference systems; accommodates both refillable and gel-filled electrolytes per ISO 17025-compliant probe selection.
• Conductivity measurement range: 0.01 µS/cm to 500 mS/cm (dependent on cell constant); auto-ranging conductivity cell detection via integrated K-factor recognition.
• Dissolved oxygen measurement: Polarographic (Clark-type) or optical (luminescence-based) probe compatibility; temperature and salinity compensation algorithms embedded per ASTM D888 and ISO 5814.
• Calibration flexibility: Up to five-point pH calibration with four factory-defined buffer groups (including DIN, NIST, US, and Chinese standard sets); conductivity cell constant verification with KCl standard solutions.
• Environmental resilience: Operating temperature range of 0–40 °C ambient; storage range up to 105 °C for probe conditioning; humidity tolerance up to 80% RH non-condensing.

Sample Compatibility & Compliance

The FE28-Meter is validated for use with aqueous solutions across pharmaceutical, food & beverage, wastewater, and academic research applications. It supports direct immersion of certified METTLER TOLEDO InLab® series electrodes—including InLab® Expert Pro (pH), InLab® Cond (conductivity), and InLab® OptiOx (optical DO)—all compliant with IEC 61000-4 electromagnetic immunity standards. The instrument meets CE marking requirements under the EU Electromagnetic Compatibility Directive 2014/30/EU and Low Voltage Directive 2014/35/EU. Its calibration traceability aligns with ISO/IEC 17025:2017 clause 6.4.10 for measurement equipment management, and data integrity features satisfy audit requirements under FDA 21 CFR Part 11 when paired with METTLER TOLEDO LabX® Lite software (optional). No internal battery charging circuitry is included; power is supplied via external 12 V DC adapter or USB bus power.

Software & Data Management

The FE28-Meter stores up to 200 measurement records with timestamps, electrode IDs, calibration parameters, and user-defined sample IDs. All stored entries include metadata such as temperature at time of measurement, calibration date, and sensor serial number—enabling full analytical traceability. Data export is supported via RS232 (9600 baud, no parity, 8N1) or USB virtual COM port to spreadsheet or LIMS-compatible formats (CSV, TXT). While the device lacks built-in Wi-Fi or Ethernet, it interoperates with METTLER TOLEDO’s LabX® Lite PC software for automated report generation, electronic signature capture, and audit trail archiving—meeting GLP and GMP documentation expectations. Firmware updates are performed offline using USB memory devices and require administrator-level access credentials.

Applications

• Pharmaceutical water system validation (PW, WFI): Monitoring pH and conductivity per USP and EP 2.2.38 specifications.
• Wastewater treatment plant effluent testing: Field-deployed DO and pH profiling during aeration basin optimization.
• Food processing line QC: Rapid verification of brine conductivity and marinade pH prior to thermal processing.
• Academic teaching labs: Student experiments involving titration endpoint detection, buffer capacity analysis, and ionic strength effects on redox potential.
• Environmental field surveys: Stream and lake DO saturation assessment with barometric pressure and salinity correction applied in real time.

FAQ

Does the FE28-Meter support automatic temperature compensation for all three parameters?

Yes—ATC is enabled by default for pH and conductivity using an integrated Pt1000 thermistor; DO compensation uses the same sensor input but applies separate thermodynamic correction models per ISO 5814.
Can third-party electrodes be used with this meter?

Only METTLER TOLEDO InLab® and SevenCompact™-compatible electrodes are fully supported; non-OEM probes may lack K-factor encoding or reference junction diagnostics required for error-free operation.
Is the instrument suitable for ISO 17025-accredited laboratories?

Yes—when operated with documented procedures, certified reference materials, and regular inter-laboratory verification, the FE28-Meter satisfies ISO/IEC 17025:2017 clause 6.4.6 for equipment suitability and performance verification.
What is the maximum cable length supported for RS232 communication?

Up to 15 meters with shielded twisted-pair cabling meeting EIA/TIA-232-F specification; longer runs require active repeaters or USB-to-serial conversion with galvanic isolation.
How often should the pH electrode be recalibrated during continuous use?

Recalibration is recommended before each analytical session and after every 10–15 measurements, or whenever drift exceeds ±0.05 pH units from initial calibration—per ASTM E70 guidance for routine pH metrology.