Hanna HI2211 Benchtop pH/ORP/Temperature Meter

Overview

The Hanna HI2211 is a precision benchtop electrochemical meter engineered for routine laboratory measurement of pH, oxidation-reduction potential (ORP), and temperature in aqueous and semi-aqueous samples. It operates on the fundamental principle of potentiometric measurement: pH is determined via the Nernst equation using a glass electrode and reference junction, while ORP relies on the reversible redox couple’s potential relative to a stable Ag/AgCl reference system. Temperature is measured concurrently using a Pt1000 or thermistor-based probe, enabling real-time compensation of electrode response kinetics and liquid junction potential. Designed for compliance-critical environments, the HI2211 incorporates GLP (Good Laboratory Practice) functionality—including timestamped calibration logs, electrode performance tracking, and expiration alerts for calibration standards—ensuring traceability and audit readiness per ISO/IEC 17025 and FDA 21 CFR Part 11 requirements when paired with validated software workflows.

Key Features

• High-impedance input circuitry (≥10¹² Ω) minimizes loading error and supports high-resistance pH electrodes, including double-junction and low-maintenance gel-filled sensors.
• Intelligent auto-recognition of NIST-traceable calibration buffers (pH 4.01, 6.86, 7.01, 9.18, 10.01) reduces operator dependency and mitigates mis-calibration risk.
• Dual-range ORP measurement (±399.9 mV at 0.1 mV resolution; ±2000 mV at 1 mV resolution) accommodates both conventional redox titrations and aggressive industrial effluent monitoring.
• Configurable temperature compensation: automatic (using integrated or external probe) or manual entry, covering -20.0 to 120.0 °C to support applications from cryogenic buffer verification to hot-process water analysis.
• Backlit graphical LCD with intuitive step-by-step on-screen prompts guides users through calibration, measurement, and diagnostics—reducing training overhead and inter-operator variability.
• GLP-compliant data handling: stores up to 200 measurement records with date/time stamps, electrode ID (if encoded), calibration history, and ambient temperature—exportable via optional RS232 interface for LIMS integration.

Sample Compatibility & Compliance

The HI2211 is validated for use with standard BNC-compatible pH and ORP electrodes across diverse matrices: potable and wastewater, food homogenates (e.g., dairy, juice, meat extracts), pharmaceutical buffers (USP ), and electroplating baths. Its extended pH range (-2.00 to 16.00) enables measurement in concentrated alkalis (e.g., NaOH scrubber solutions) and strong acids (e.g., HCl regeneration streams), provided appropriate electrode selection (e.g., HF-resistant glass, refillable double-junction). The instrument meets IEC 61010-1 safety standards for laboratory electrical equipment and supports method validation per ASTM D1293 (pH of water) and EPA Method 9040C (ORP in environmental samples). All calibrations are referenced to NIST/USA-certified standard solutions, ensuring metrological traceability to national standards.

Software & Data Management

While the HI2211 operates as a standalone meter, its RS232 serial output (optional cable required) enables direct connection to PCs running Hanna’s HI92000 Windows software or third-party SCADA/LIMS platforms. This interface supports automated data logging, report generation (PDF/CSV), and electronic signature capture for 21 CFR Part 11 compliance. Calibration records include slope (%), offset (mV), and asymmetry potential—critical parameters for assessing electrode health and determining replacement intervals. Audit trails log all user-initiated actions (e.g., calibration start/end, parameter changes), satisfying GLP documentation requirements for regulated laboratories engaged in environmental testing, QC release, or method development.

Applications

• Environmental labs: Monitoring pH and redox status in surface water, groundwater, and leachate per EPA and EU WFD protocols.
• Food & beverage QA/QC: Verifying acidification endpoints in fermentation (yogurt, wine), shelf-life stability testing, and rinse water neutrality checks.
• Pharmaceutical manufacturing: Conducting pH verification of purified water (PW) and water-for-injection (WFI) systems per USP .
• Academic research: Teaching core electrochemistry principles—including Nernstian behavior, junction potentials, and temperature effects on electrode response—in undergraduate analytical chemistry labs.
• Industrial process control: Routine checks of cleaning-in-place (CIP) solution concentration, boiler feedwater alkalinity, and wastewater neutralization efficiency.

FAQ

What calibration standards are supported, and how is traceability ensured?
The HI2211 is pre-programmed for five NIST/USA-traceable pH buffers (4.01, 6.86, 7.01, 9.18, 10.01) and accepts custom calibration points. Traceability is maintained by using certified reference materials with documented uncertainty and lot-specific certificates.
Can the instrument store calibration data for multiple electrodes?
No—the HI2211 does not assign unique IDs to electrodes. However, each calibration event is time-stamped and includes slope, offset, and temperature, allowing manual correlation with electrode usage logs.
Is manual temperature compensation sufficient for regulatory submissions?
Yes, provided the entered temperature value is verified independently (e.g., with a calibrated thermometer) and documented. Automatic compensation is recommended for dynamic samples where thermal gradients may affect reading stability.
What maintenance is required to sustain ±0.01 pH accuracy?
Daily rinsing with deionized water, weekly storage in 3 M KCl (not DI water), and monthly cleaning with appropriate agents (e.g., pepsin/HCl for protein fouling, thiourea for sulfide deposits) are essential. Electrode slope should be monitored; values below 92% warrant reconditioning or replacement.
Does the HI2211 meet FDA 21 CFR Part 11 requirements out-of-the-box?
The meter itself provides audit-trail-capable logging, but full Part 11 compliance requires validated software (e.g., HI92000), electronic signatures, and administrative controls—implemented at the system level, not the device level.