LOI Limiting Oxygen Index Chamber - QualiLOI™ Series
QualiLOI™ Series — ASTM D2863, ISO 4589-2 & NES 714 Compliant Flammability Testing
The Limiting Oxygen Index (LOI) test is the most economical and precise quality-control test for combustible materials available to modern laboratories. By measuring the minimum oxygen concentration — expressed as a volume percentage in a flowing oxygen + nitrogen mixed-gas stream — required to just sustain combustion of a vertically mounted specimen, the LOI test provides a single objective number that quantifies how flame-retardant a material is. Since the atmosphere is approximately 21% oxygen, materials with an LOI above 21% are self-extinguishing in air, while materials below 21% will continue to burn once ignited. This deceptively simple test has become the dominant primary characterization and quality-control tool across the plastic-materials, electric-cable, polymer-compounding, and flame-retardant-additive industries worldwide — and the foundational input to UL94 final-product certification programs.
Qualitest offers a comprehensive QualiLOI™ Series Limiting Oxygen Index Chamber portfolio engineered to match every laboratory size, throughput, and accuracy requirement. The basic QualiLOI™ Limiting Oxygen Index Chamber is the economical and versatile platform for evaluating combustion performance of plastics, rubber, fiber, foamed plastics, film, textile, wood, and other combustible materials — accurate, reproducible, convenient, and fast, with full ASTM D2863, ISO 4589-2, and NES 714 compliance. The mid-range QualiLOI-PM (Paramagnetic Type) features a paramagnetic oxygen cell delivering precise oxygen-level assessment with less than 0.1% error, digital display of nitrogen flow and total O₂/N₂ flow, automatic O₂% display during the test (no calculations needed), high-temperature-resistant quartz glass tube, easy flame-length adjustment, sample holders for both rigid and flexible specimens, and a shortened gas path for quicker response times. And the flagship QualiLOI-Auto Automatic Limiting Oxygen Index Chamber adds a touchscreen interface with one-click ratio display of oxygen percentage concentration (eliminating manual adjustments and calculations), gas ignition with adjustable flame length and gas-source cutoff, sample holders for both supportable and unsupportable specimens, and automatic adjustment of quartz cylinder height for easy sample replacement — combining paramagnetic precision with full process automation.
Paramagnetic oxygen sensor technology is the analytical foundation of every premium LOI tester worldwide — and the defining advantage of the QualiLOI-PM and QualiLOI-Auto platforms. Unlike traditional electrochemical oxygen sensors that degrade over time and require frequent replacement, paramagnetic sensors are non-depleting, maintaining roughly 0.1% measurement accuracy for years without sensor replacement. This eliminates one of the largest hidden lifecycle costs of LOI testing, dramatically improves long-term data consistency, and makes paramagnetic LOI testers the preferred standard for high-volume testing laboratories supporting regulatory compliance, materials certification, and ongoing R&D programs.
Applications in Industries
- Plastics & Polymer Manufacturing — Flame-retardancy QC of rigid plastics, engineering polymers, polyolefins, ABS, PC, PVC, polyamides, polyesters, and specialty resins per ASTM D2863 and ISO 4589-2.
- Electric Cable & Wire Industry — LOI characterization of cable jacketing, insulation compounds, low-smoke zero-halogen (LSZH) materials, and fire-resistant cable formulations critical to building, transport, and electrical infrastructure.
- Rubber & Elastomer Industry — Combustion-performance qualification of vulcanized rubber, thermoplastic elastomers, sealing compounds, and elastomeric components for transportation, aerospace, and industrial applications.
- Foamed Plastics & Insulation — Flame-retardancy testing of polyurethane foams, polystyrene insulation, EPS, XPS, polyisocyanurate boards, and building-insulation foamed products.
- Textiles, Fibers & Apparel — LOI screening of technical textiles, protective workwear, upholstery fabrics, carpets, awnings, and aerospace/transportation interior materials.
- Films & Flexible Packaging — Combustion-behavior verification of polymer films, multi-layer laminates, agricultural films, and specialty packaging materials.
- Building & Construction Materials — Fire-safety characterization of plastic profiles, sealants, geomembranes, roofing components, and architectural plastics under regulatory fire-code requirements.
- Aerospace, Defense & Transportation — Flammability qualification of aircraft interior materials, defense-equipment polymers, and rail/automotive interior components per NES 714 and related standards.
- Flame-Retardant Additive Development — R&D evaluation of brominated, phosphorus-based, mineral-filler, and intumescent flame-retardant additive performance during compound development.
- Universities & Third-Party Testing Labs — Materials-research, regulatory test-house operations, polymer-combustion graduate research, and commercial certification labs supporting brand owners worldwide.
Product Comparison Table
Specification | QualiLOI™ (Basic / Economical) | QualiLOI™-PM (Paramagnetic) | QualiLOI™-Auto (Automatic Premium) |
Product Tier | Economical and versatile basic LOI chamber | Mid-range paramagnetic-sensor LOI tester | Premium fully-automatic LOI chamber with touchscreen |
Oxygen Sensor Type | Standard oxygen sensor for routine combustion measurement | Paramagnetic oxygen cell — precise, long lifespan, low error rate, high reliability | Paramagnetic Type oxygen sensor — precision, durability, low error rate, high reliability |
Oxygen Measurement Accuracy | Accurate and reproducible volume-percent oxygen concentration determination | < 0.1% error — precise oxygen-level assessment for years without sensor replacement | < 0.1% error — high accuracy across long-duration testing campaigns |
Standards Compliance | ASTM D2863, ISO 4589-2, NES 714 | ASTM D2863, ISO 4589-2, NES 714 + extended international compliance | ASTM D2863, ISO 4589-2, NES 714 |
Display & Interface | Digital displays for clear measurement readout | Digital display of N₂ flow + total O₂/N₂ flow; direct O₂% display during test — no calculations needed | Touchscreen interface; one-click setting for automatic ratio display of O₂ percentage — eliminates manual calculations |
Quartz Cylinder / Glass Tube | Standard quartz glass for combustion observation | High-temperature-resistant quartz glass tube — withstands elevated test temperatures | High-temperature heat-resistant quartz glass cylinder for demanding test conditions |
Ignition System | Standard gas ignition for sample combustion | Gas ignition device with easy flame-length adjustment | Gas ignition device with adjustable flame length + gas-source cutoff capability |
Sample Holders | Standard sample holders for diverse materials | Holders for both rigid and flexible samples | Holders for both supportable and unsupportable samples |
Cylinder Height Adjustment | Manual height adjustment | Manual height adjustment with shortened gas path for quicker response times | Automatic adjustment of quartz cylinder height for easy sample replacement |
Material Versatility | Plastics, rubber, fiber, foamed plastics, film, textile, wood, and more | Plastics, rubber, films, foams, textiles, cables, and other solid combustible materials | Full polymer & composite spectrum — automated workflow for high-volume QC operations |
Primary Use Case | Flame-retardancy identification + research — accurate, reproducible, convenient, fast measurement | Long-life precision LOI measurement without recurring sensor-replacement cost | High-throughput regulatory QC — automated workflow eliminates manual O₂% calculations |
Best Suited For | Universities, small QC labs, R&D — flame-retardancy screening and research applications | High-volume testing labs needing the highest precision, sensor longevity, and lowest lifecycle cost | Regulatory QC, certification labs, plastics & cable manufacturers needing streamlined automated testing |
Why Choose Qualitest for Your LOI Testing Needs
Qualitest is a globally recognized supplier of advanced flammability and materials-testing instruments, serving customers worldwide with one of the most comprehensive Limiting Oxygen Index Chamber portfolios available.
Three-Tier Portfolio — One Trusted Source
From the economical and versatile basic QualiLOI™, through the paramagnetic-precision QualiLOI-PM, to the flagship fully-automatic QualiLOI™-Auto with touchscreen interface and automatic cylinder-height adjustment — Qualitest offers a coordinated portfolio matching every laboratory size, throughput, budget, and automation requirement. A single trusted supplier simplifies procurement, training, sensor support, and standardization across your entire flammability-testing infrastructure.
Paramagnetic Oxygen Sensor Superiority
The QualiLOI™-PM and QualiLOI™-Auto incorporate paramagnetic Type oxygen sensors — non-depleting, long-lifespan technology maintaining roughly 0.1% measurement accuracy for years without sensor replacement. This eliminates the recurring sensor-replacement cost, calibration downtime, and progressive accuracy degradation that plague traditional electrochemical-sensor LOI testers — delivering dramatically lower total cost of ownership across the instrument lifecycle.
Full International Standards Compliance
Every QualiLOI™ platform is engineered to meet the most demanding global flammability-testing standards — ASTM D2863 (Standard Test Method for Measuring the Minimum Oxygen Concentration to Support Candle-Like Combustion of Plastics), ISO 4589-2 (Plastics — Determination of Burning Behaviour by Oxygen Index — Ambient-Temperature Test), and NES 714 (Naval Engineering Standard for combustion-performance testing) — ensuring every test result is universally accepted, audit-ready, and defensible in customer certifications and regulatory submissions.
Streamlined Automation Saves Time
The flagship QualiLOI™-Auto delivers one-click setting of oxygen percentage with automatic ratio display — eliminating manual gas-flow calculations, reducing per-test setup time, and removing operator-introduced calculation errors. Combined with automatic quartz-cylinder height adjustment for easy sample replacement, the QualiLOI™-Auto can dramatically increase laboratory throughput while reducing operator workload.
Versatile Sample Compatibility
Qualitest LOI chambers test the full breadth of combustible materials — plastics, rubber, fiber, foamed plastics, film, textile, wood, cables, and composites — with sample holders for both rigid (supportable) and flexible (unsupportable) specimens. High-temperature-resistant quartz glass cylinders withstand demanding test conditions across long-duration campaigns and elevated-temperature variants.
Adjustable Ignition for Repeatable Combustion
Every QualiLOI™ platform features a gas ignition device with adjustable flame-length control — ensuring consistent ignition geometry across every test, every operator, every batch. The QualiLOI™-Auto adds a gas-source cutoff capability for enhanced operator safety and precise gas-flow control during automated cycles.
Cost-Effective Value & Global Support
Qualitest delivers premium LOI testing performance at a transparent, competitive price point — backed by global service, training, calibration support, and worldwide stocked accessories. The economical QualiLOI™ basic model brings entry-level LOI capability within reach of universities and small QC labs, while the paramagnetic QualiLOI™-PM and QualiLOI™-Auto deliver the long-term lifecycle savings that high-volume regulatory laboratories require.
Identify Flame Retardancy. Certify Fire Safety.
In every industry where polymers, plastics, rubber, cables, textiles, and composites are used — automotive, aerospace, construction, electronics, transportation, marine — fire safety is not just a regulatory requirement, it is a foundational engineering responsibility. A material that ignites too easily means cable-tray fires that propagate through buildings, aircraft-interior failures that cost lives, electronic housings that turn small electrical faults into catastrophic blazes, and construction products that fail building-code certification. The plastics manufacturers, cable producers, compounders, and QC laboratories that consistently deliver flame-retardant, regulator-compliant, fire-safe products are the ones equipped with LOI chambers built for precision, paramagnetic accuracy, and full international-standards compliance — and the Qualitest QualiLOI™ portfolio gives you exactly that.
Whether you are screening flame-retardant additives during compound development, certifying cable jacketing for an electrical-infrastructure project, qualifying interior plastics for aircraft or rail applications, or running fundamental polymer-combustion research, Qualitest has the LOI testing platform engineered to meet your exact needs. From the economical QualiLOI™ basic chamber to the precision-paramagnetic QualiLOI™-PM and the flagship fully-automatic QualiLO™I-Auto, every Qualitest LOI chamber delivers world-class flammability-testing performance backed by industry-leading service and support.
