NETZSCH LOI Oxygen Index Analyzer

Overview

The NETZSCH LOI Oxygen Index Analyzer is a precision-engineered instrument designed to determine the Limiting Oxygen Index (LOI) of solid combustible materials according to internationally recognized combustion safety standards. Based on the principle of upward flame propagation in a vertically oriented sample column under controlled oxygen–nitrogen gas mixtures, the LOI value represents the minimum volume percentage of oxygen in the mixture required to support candle-like burning of the material for at least 3 minutes or over a defined length (typically 50 mm). This measurement provides a quantitative, reproducible indicator of relative flammability—critical for regulatory compliance, material development, and fire risk assessment in industrial R&D and quality control laboratories.

Key Features

• Paramagnetic oxygen sensor technology ensures high accuracy (±0.1% O₂) and long-term stability without sensor drift or frequent recalibration.
• Integrated color high-resolution touchscreen interface enables intuitive navigation, real-time gas composition monitoring, and direct access to test protocols and historical results.
• Automated calibration routine—including zero-point verification with nitrogen and span adjustment with certified reference gas—minimizes operator dependency and enhances inter-laboratory reproducibility.
• Dual sample holder configuration supports both supported (e.g., rigid plastics, films) and unsupported (e.g., foams, textiles, thin fibers) specimens, accommodating diverse geometries per ISO 4589-2 Annex A and B requirements.
• Compact benchtop design (360 × 360 × 630 mm) integrates a standardized 75 mm diameter × 450 mm height glass combustion column, optimized for laminar flow and uniform gas distribution during testing.
• Native USB and Ethernet connectivity enable seamless integration into laboratory networks, supporting remote operation, centralized data logging, and audit-ready export formats (CSV, PDF).

Sample Compatibility & Compliance

The LOI analyzer is validated for use across a broad spectrum of polymeric and fibrous materials—including thermoplastics, elastomers, polyurethane foams, cellulose-based papers, nonwovens, and synthetic textiles—as specified in ISO 4589-2:2017, ASTM D2863–22, and DIN 22117. Sample preparation follows strict dimensional tolerances (e.g., 150 mm × 10 mm × thickness ≤ 10.5 mm for rigid specimens), ensuring consistent heat feedback and flame dynamics. All hardware components—including gas manifolds, flow controllers, and ignition system—meet CE marking requirements and are constructed from corrosion-resistant stainless steel and borosilicate glass to maintain integrity under repeated thermal cycling and oxidative environments.

Software & Data Management

The embedded firmware implements full GLP-compliant data handling: each test record includes timestamped metadata (operator ID, ambient temperature/humidity, gas cylinder lot numbers, calibration history), raw O₂ concentration curves, and pass/fail determination logic aligned with standard acceptance criteria. Audit trails are immutable and exportable; optional software packages extend functionality to include statistical process control (SPC) charting, multi-instrument fleet management, and 21 CFR Part 11–compliant electronic signatures for regulated pharmaceutical and aerospace applications.

Applications

• Formulation screening of flame-retardant additives in polymer composites
• Comparative flammability ranking of textile blends for automotive interior specifications (e.g., FMVSS 302, UN ECE R118)
• Quality assurance of cable jacketing materials against IEC 60332–1–2 vertical flame spread requirements
• Regulatory submission support for building product classifications (EN 13501–1, ASTM E84)
• Research into pyrolysis kinetics and char-forming behavior of bio-based polymers

FAQ

What standards does the NETZSCH LOI analyzer comply with?
ISO 4589-2:2017, ASTM D2863–22, DIN 22117, and relevant clauses of EN ISO 11925–2 for preliminary ignitability screening.
Is the instrument suitable for testing thin films or low-density foams?
Yes—the dual-sample-holder system includes dedicated fixtures for unsupported specimens, and the paramagnetic sensor’s fast response time (<1 s) captures transient O₂ depletion during brief flaming events.
Can test data be integrated into LIMS or ERP systems?
Yes—via standard Ethernet TCP/IP protocols and configurable CSV/JSON export templates compatible with common laboratory informatics platforms.
Does the system require external gas cylinders or regulators?
It operates with standard compressed O₂ and N₂ supply lines; integrated mass flow controllers and pressure-sensing valves eliminate the need for external regulators.
How often must the oxygen sensor be calibrated?
Automated daily zero-and-span calibration is recommended; full sensor verification using traceable reference gases is advised every 6 months or after 200 test cycles, per ISO/IEC 17025 internal quality procedures.