Metrohm 826 Portable pH Meter

Overview

The Metrohm 826 Portable pH Meter is a field-deployable, high-precision electrochemical instrument engineered for reliable pH, redox potential (mV), and temperature measurements in demanding laboratory, industrial, and environmental applications. Based on potentiometric measurement principles—utilizing a glass electrode and reference system conforming to ISO 3696 and ASTM E70—the 826 delivers traceable, reproducible results across aqueous and semi-aqueous matrices. Its dual-temperature-sensing capability supports both Pt1000 and NTC probe configurations, enabling accurate thermal compensation under extreme conditions—from cryogenic process streams to high-temperature sterilization validation points. Designed and manufactured in Herisau, Switzerland, the instrument complies with IEC 61010-1 safety standards and meets electromagnetic compatibility (EMC) requirements per EN 61326-1 for use in regulated environments.

Key Features

• True portable architecture: Compact, lightweight housing (approx. 220 g) with integrated ergonomic grip and splash-resistant front panel (IP54-rated enclosure)
• Infrared (IrDA) communication interface compliant with IrDA 1.1 standards—enables secure, cable-free data exchange with Metrohm-certified thermal printers (e.g., PT-100) and Windows-based PCs running LabX Lite or tiamo™ software
• Extended measurement ranges: pH from –8.000 to 22.000 (calibration-dependent); ±1200.0 mV redox; temperature coverage spanning –150.0 to +250.0 °C with Pt1000, or –5.0 to +250.0 °C with NTC sensors
• High-resolution display: 4-digit alphanumeric LCD with backlight, supporting simultaneous readout of pH/mV, temperature, and electrode status indicators (e.g., slope, offset, response time)
• Calibration flexibility: Supports 1–3 point pH calibration using standard buffers (NIST-traceable or DIN 19266 compliant); automatic recognition of buffer values via electrode ID chip (when used with SmartChem electrodes)
• Battery-powered operation: Rechargeable Li-ion battery providing ≥100 hours of continuous use; USB-C charging port with status LED indicator

Sample Compatibility & Compliance

The Metrohm 826 is validated for use with standard combination pH electrodes (e.g., Metrohm’s Hydron, Aquatrode Plus, or InLab® series) and compatible reference electrodes. It supports routine analysis of aqueous solutions, food extracts, wastewater, pharmaceutical buffers, and mild organic solvent mixtures (<20% v/v ethanol or methanol). Electrode compatibility adheres to DIN EN ISO 17442 for electrode performance verification. The instrument meets GLP documentation requirements through timestamped, non-editable measurement logs stored internally (up to 500 records). While not inherently 21 CFR Part 11 compliant in standalone mode, full audit trail functionality—including user login, electronic signature, and data integrity controls—is enabled when paired with Metrohm LabX software in networked lab environments.

Software & Data Management

Data acquisition and reporting are supported via infrared link to Metrohm’s proprietary software ecosystem. LabX Lite provides basic export (CSV, TXT) and calibration report generation, while full LabX or tiamo™ installations enable automated method execution, statistical trend analysis (e.g., control charts per ISO 5725), and integration into LIMS workflows. All exported datasets include embedded metadata: measurement timestamp (UTC), operator ID, electrode serial number, calibration history, and environmental temperature at time of reading. Internal memory retains raw readings with ISO 8601-formatted timestamps and supports manual annotation via alphanumeric keypad.

Applications

• Field-based water quality monitoring (surface water, groundwater, effluent discharge points) per EPA Method 150.1 and ISO 10523
• In-process pH control during bioreactor cultivation, fermentation, and downstream purification in cGMP-compliant biopharma manufacturing
• Raw material testing and formulation QC in food & beverage production (e.g., dairy acidification, juice titratable acidity verification)
• Educational laboratories requiring rugged, intuitive instrumentation for undergraduate electrochemistry curricula
• Environmental site assessment where portability and rapid thermal equilibration are critical—such as soil pore-water extraction or sediment interstitial fluid analysis

FAQ

Is the Metrohm 826 suitable for non-aqueous pH measurements?

The instrument is calibrated and validated for aqueous systems. For non-aqueous or mixed-solvent samples, electrode selection, calibration protocol, and interpretation must follow ISO 17442 Annex B guidelines—and results should be reported as “apparent pH” with full method documentation.
Does the 826 support automatic temperature compensation (ATC) with all electrode types?

Yes—ATC is active whenever a temperature probe (integrated or external Pt1000/NTC) is connected and recognized. Slope correction is applied in real time using the Nernst equation with configurable temperature coefficient.
Can measurement data be exported directly to Excel without proprietary software?

Yes—via IrDA to a Windows PC running standard terminal emulation software (e.g., PuTTY configured for IrDA COM port), the device outputs ASCII-formatted data streams compatible with spreadsheet import.
What is the recommended recalibration frequency for routine QC use?

Per ISO/IEC 17025:2017 Clause 7.7, recalibration is required before each analytical batch, after electrode replacement, following exposure to extreme pH or temperature, and at least every 24 hours during continuous operation.
Is firmware upgrade supported in the field?

Firmware updates are performed via USB-C connection using Metrohm’s official Update Manager tool; infrared interface does not support firmware transmission for security reasons.