Koehler K10290 Automatic Aniline Point Tester

Overview

The Koehler K10290 Automatic Aniline Point Tester is a precision-engineered instrument designed for the standardized determination of aniline point in petroleum products, including lubricating oils, diesel fuels, and hydrocarbon solvents. The aniline point serves as a critical empirical indicator of aromatic content and polarity in hydrocarbon mixtures—directly correlating with solvency power, compatibility with elastomers, and refining severity. This instrument operates on the classical two-phase equilibrium principle defined in ASTM D611, ISO 2977, and IP 2: a precisely metered volume of aniline is mixed with the sample (or sample-diluted with n-heptane), heated until complete miscibility is achieved, then cooled at a controlled rate (typically 1°C/min) to detect the temperature at which phase separation reappears—the aniline point. Unlike manual methods, the K10290 eliminates operator subjectivity through automated sample handling, precise thermal ramping, and optical detection of phase boundary formation.

Key Features

• Automated sample introduction and mixing sequence, minimizing human error and ensuring repeatability across operators and shifts
• Wide operational temperature range from 0 °C to 150 °C (32 °F to 302 °F), accommodating both low-aniline-point heavy distillates and high-aniline-point paraffinic base stocks
• Digital high-resolution temperature display (0.1 °C resolution, 0–999.9 °C range) with NIST-traceable calibration capability
• Optically enhanced phase-separation detection system utilizing LED illumination and photodiode sensing for unambiguous endpoint identification—even in dark or turbid samples
• Robust stainless-steel reaction chamber and thermally insulated sample path engineered for long-term stability under repeated thermal cycling
• Compliance-ready design supporting audit trails for GLP and refinery QA/QC environments

Sample Compatibility & Compliance

The K10290 accommodates a broad spectrum of petroleum-based liquids—from colorless naphthas to deeply colored cracked stocks—without requiring dilution or filtration in most cases. Its optical detection algorithm compensates for inherent sample opacity, enabling reliable aniline point determination per ASTM D611 Section 8 (for dark oils) and ISO 2977 Annex A. The instrument meets all mechanical and procedural requirements specified in ASTM D611, IP 2, DIN 51775, FTM 791-3601, and NF M 07-021. It supports method validation documentation packages required for ISO/IEC 17025-accredited laboratories and integrates with LIMS via RS-232 serial output for traceable data capture.

Software & Data Management

While the K10290 operates as a standalone benchtop unit with embedded firmware, it provides real-time ASCII-formatted output (temperature vs. time) via RS-232 interface. This enables direct integration with laboratory data systems or third-party acquisition software for automated report generation, trending analysis, and compliance archiving. All test parameters—including heating/cooling rates, sample ID, operator code, and timestamp—are logged internally and exportable. The system supports 21 CFR Part 11–compatible electronic signatures when paired with validated host software, fulfilling FDA-regulated refinery QC workflows and internal GMP documentation standards.

Applications

• Refinery process control: Monitoring aromatic saturation levels in hydrotreated feedstocks and finished lubricant base oils
• Fuel formulation: Assessing diesel blendstock compatibility and predicting low-temperature operability
• Quality assurance of industrial solvents: Verifying aromatic content consistency for paint, ink, and adhesive manufacturing
• Research & development: Correlating aniline point with HPLC-based aromatic quantification (e.g., ASTM D1319) or simulated distillation profiles
• Contract testing laboratories: Delivering accredited aniline point results compliant with API RP 4200 and ASTM D611 reporting requirements

FAQ

What standards does the K10290 fully support?
ASTM D611, IP 2, ISO 2977, DIN 51775, FTM 791-3601, and NF M 07-021—all verified through Koehler’s factory performance qualification protocol.
Can the instrument handle highly viscous or waxy samples?
Yes; preheating functionality allows samples up to 150 °C to be introduced in molten state, and the agitator ensures homogeneous mixing prior to cooling cycle.
Is external calibration verification possible?
Yes; the unit accepts certified reference materials (CRMs) traceable to NIST SRM 1635a (aniline) and includes built-in calibration offset adjustment for field verification.
Does the K10290 require routine maintenance beyond cleaning?
No consumables are used; only periodic verification of temperature sensor accuracy and optical window cleanliness is recommended per ASTM E77 guidelines.
How is data integrity ensured during power interruption?
Non-volatile memory retains all test logs and configuration settings; active tests resume from last recorded temperature point upon restart.