Hanna HI991001N Portable pH and Temperature Meter

Overview

The Hanna HI991001N is a rugged, field-deployable portable pH and temperature meter engineered for precision electrochemical measurement in demanding environments—from wastewater treatment plants and food processing lines to environmental monitoring sites and educational laboratories. It operates on the fundamental principle of potentiometric pH measurement: the instrument measures the potential difference (in mV) between a glass pH sensing electrode and a reference electrode immersed in solution, then converts this voltage into pH units using the Nernst equation with automatic temperature compensation (ATC). The integrated Pt1000 temperature sensor within the HI1296D probe ensures real-time, high-fidelity thermal correction across the full operational range (−5.0 to 105.5 °C), eliminating manual correction errors and supporting traceable, reproducible results compliant with ISO 8655-4, ASTM D1293, and USP . Designed for GLP-ready workflows, the HI991001N features stable endpoint detection, buffer recognition logic, and on-screen calibration diagnostics—critical for maintaining data integrity in regulated QC/QA settings.

Key Features

• Rugged IP67-rated housing with ergonomic, one-handed operation and large backlit LCD display for readability under low-light or outdoor conditions
• Automatic 1- or 2-point pH calibration with intelligent buffer recognition for pH 4.01, 6.86, 7.01, 9.18, and 10.01—eliminating manual buffer selection errors
• High-resolution measurement: 0.01 pH resolution and 0.1 °C/°F temperature resolution ensure fine-grained process control
• Stainless steel-bodied HI1296D combination electrode with integrated Pt1000 temperature sensor—optimized for durability in abrasive, high-salinity, or viscous media
• Automatic Temperature Compensation (ATC) algorithm compliant with IUPAC-recommended thermistor response models, validated over −5.0 to 105.0 °C
• Built-in stability indicator and calibration status flag—providing immediate visual feedback on measurement readiness and electrode health

Sample Compatibility & Compliance

The HI991001N supports direct immersion measurements in aqueous solutions, slurries, semi-solids (e.g., cheese, soil extracts), and industrial effluents. Its HI1296D electrode features a double-junction reference system and ceramic junction optimized for long-term stability in samples containing sulfides, proteins, or heavy metals—reducing clogging and junction potential drift. The instrument complies with CE, RoHS, and FCC directives. Calibration traceability aligns with NIST SRM 186, NIST SRM 187, and USA-standard buffer formulations per ASTM E2117. Data output meets basic GLP documentation requirements, including timestamped calibration logs and user-defined ID entry—supporting audit readiness for ISO/IEC 17025-accredited laboratories.

Software & Data Management

While the HI991001N operates as a standalone field instrument without onboard memory or Bluetooth connectivity, it is fully compatible with Hanna’s HI9828 interface cable and HI92000 Windows-based software (sold separately) for advanced data logging, report generation, and compliance archiving. When connected, users can export calibration records, measurement histories, and electrode diagnostics—including slope (%), offset (mV), and ATC validation points—in CSV or PDF formats. All exported files include embedded timestamps, operator ID fields, and instrument serial number metadata—enabling full traceability under FDA 21 CFR Part 11 (with appropriate system configuration and electronic signature controls).

Applications

• Environmental field testing: surface water, groundwater, leachate, and stormwater pH profiling per EPA Method 9040C
• Food & beverage QA: pH verification of dairy products, fermented foods, sauces, and brines—critical for HACCP and shelf-life modeling
• Pharmaceutical manufacturing: raw material and cleaning validation rinse water testing per USP and EP 2.2.3
• Education and vocational training: hands-on electrochemistry instruction with robust hardware resistant to student handling
• Municipal water/wastewater operations: continuous monitoring of influent, effluent, and digester sludge pH during biological treatment processes

FAQ

What calibration standards are supported?
The HI991001N recognizes NIST-traceable or USA-standard pH buffers at 4.01, 6.86, 7.01, 9.18, and 10.01—automatically detecting and assigning calibration points during setup.
Is the HI1296D electrode suitable for non-aqueous or high-viscosity samples?
The HI1296D is designed for aqueous and mildly viscous media; for solvents, oils, or highly viscous gels, Hanna recommends the HI1131B or HI1083B electrodes with specialized junctions and filling solutions.
How often should calibration be performed?
Calibration frequency depends on application criticality and sample matrix; Hanna recommends daily calibration for regulated QC work, and pre- and post-measurement calibration for high-accuracy field campaigns.
Does the instrument support GLP-compliant record keeping?
Yes—when used with HI92000 software, all calibrations and measurements are timestamped, user-annotated, and exportable with full metadata for audit trails compliant with ISO/IEC 17025 and FDA 21 CFR Part 11.
Can the HI991001N measure outside the −2.00 to 16.00 pH range?
No—the meter is electronically limited to this range; measurements beyond these values will display “LO” or “HI” and are not valid per electrode Nernstian response limits and glass membrane stability constraints.