Karrie KA-131T Automated Total Acid Number (TAN) Analyzer for Jet Fuels
| Brand | Karrie |
|---|---|
| Model | KA-131T |
| Power Supply | AC 220 V ±10%, 50 Hz |
| Power Consumption | 750 W |
| Heating Method | Adjustable heating mantle (0–220 V, continuously variable) |
| Temperature Control | Solid-state voltage regulator |
| Voltage Display | Digital voltmeter |
| Stirring Method | Magnetic stirring |
| Titration Method | Linear micro-pump titration |
| Endpoint Detection | Imported colorimetric sensor |
| Communication Interface | RS-232 serial port |
| Printer | Dot-matrix printer |
| Operating Environment | 5–40 °C, ≤85% RH |
| Dimensions (W×D×H) | 300 × 510 × 680 mm |
| Weight | 13 kg |
Overview
The Karrie KA-131T Automated Total Acid Number (TAN) Analyzer is a dedicated benchtop instrument engineered for precise, reproducible determination of total acid number in aviation turbine fuels—primarily jet fuel (e.g., Jet A, Jet A-1, JP-5, and JP-8). It operates on the principle of potentiometric or colorimetric endpoint detection during potentiometric titration with standardized alcoholic potassium hydroxide (KOH) solution, fully compliant with internationally recognized standard test methods including ASTM D3242, GB/T 12574, and IP 273. The system implements a closed-loop, nitrogen-purged titration cell to minimize CO₂ interference and oxidation of sample components, ensuring measurement integrity across the low-acid range of 0.000–0.100 mg KOH/g—a critical specification for fuel stability monitoring and engine compatibility assessment per OEM and military fuel specifications (e.g., MIL-DTL-83133, DEF STAN 91-91).
Key Features
- Automated nitrogen purging sequence prior to and during titration to eliminate atmospheric carbon dioxide interference and suppress sample oxidation.
- High-precision linear micro-pump titration system with calibrated delivery accuracy and programmable flow rate control for optimal endpoint resolution.
- Imported optical colorimetric sensor for robust, drift-resistant endpoint detection—engineered for long-term stability in hydrocarbon matrix environments.
- Integrated magnetic stirrer with adjustable speed and built-in reagent dispensing module, eliminating manual handling and reducing contamination risk.
- Capacitive touchscreen interface with intuitive workflow navigation, multi-language support (English default), and non-volatile memory for up to 1,000 test records including blank values.
- Onboard calculation engine applying ASTM D974–derived algorithms for TAN computation, with automatic unit conversion (mg KOH/g) and statistical summary (mean, SD, RSD).
Sample Compatibility & Compliance
The KA-131T is validated for use with clear, bright, low-viscosity hydrocarbon-based jet fuels meeting ASTM D1655 and DEF STAN 91-91 specifications. It accommodates samples requiring minimal pretreatment—no filtration or dehydration is necessary unless particulate or water contamination exceeds 30 ppm. The analyzer meets essential requirements for laboratory quality assurance under ISO/IEC 17025:2017, supports GLP-compliant operation via audit-trail-enabled firmware (user login, timestamped actions, result locking), and provides traceable calibration logs aligned with internal SOPs. While not FDA 21 CFR Part 11–certified out-of-the-box, its RS-232 interface enables integration into validated LIMS environments where electronic record integrity is enforced at the system level.
Software & Data Management
Data export is supported via RS-232 serial communication to external PCs running proprietary Karrie DataLink software (Windows 10/11 compatible), enabling CSV-formatted report generation, trend charting over time, and batch-level statistical analysis. All measurements include embedded metadata: operator ID, sample ID, date/time stamp, ambient temperature/humidity (if logged externally), titrant concentration, blank correction value, and raw sensor response curve. Internal storage retains full test history with tamper-evident timestamps; no data overwrite occurs without explicit user authorization. Firmware updates are delivered via USB flash drive with SHA-256 checksum verification.
Applications
- Monitoring acid buildup during fuel storage and aging studies per ASTM D2274 (oxidation stability).
- Quality release testing of refinery-produced jet fuel prior to distribution or aircraft refueling.
- Investigating corrosion potential in fuel system components (e.g., aluminum alloys, elastomers) linked to organic acid content.
- Supporting root-cause analysis of filter blocking, injector fouling, or turbine deposit formation correlated with elevated TAN.
- Compliance verification for military logistics depots operating under NATO AEP-51 or U.S. Air Force TO 00-25-234.
FAQ
What titrant concentration is recommended for optimal precision in the 0.000–0.100 mg KOH/g range?
A 0.01 mol/L alcoholic KOH solution is specified in ASTM D3242 and ensures adequate titrant volume resolution while minimizing dilution error. Karrie supplies certified reference titrants traceable to NIST SRM 2242.
Can the KA-131T be used for diesel or marine fuel TAN analysis?
No—it is optimized for low-acid jet fuels only. Diesel and residual fuels typically exceed 0.100 mg KOH/g and require higher-range analyzers (e.g., ASTM D664-compliant systems) with different electrode chemistry and solvent systems.
Is method validation documentation available?
Yes—Karrie provides a comprehensive IQ/OQ protocol package, including linearity, repeatability (n=6 at three levels), intermediate precision, and robustness testing against reference materials (e.g., NIST RM 869b).
