ASTM D2863 Oxygen Index Test for Minimum Oxygen Concentration | United Test LOI Test Machine Manufacturer

Information on the most widely used ASTM standards within the materials testing industry

Descriptions of the most prominent lSO standards within the materials testing industry

Standards including EN, DIN, JlS, and more

Mechanical testing of polymer materials in the automotive industry is directly related to the safety of components and the reliability of the entire vehicle. UnitedTest can cover mechanical performance testing for automotive interior and exterior parts, as well as functional components, adapting to automaker standards and providing comprehensive testing solutions including tensile, impact, and fatigue tests.

Mechanical testing in the battery industry determines the tensile and puncture resistance of core components such as separators and electrodes, directly affecting battery safety and cycle life. UnitedTest can cover full-dimensional mechanical testing of battery materials, compatible with national and international standards, and provide customized testing solutions.

Mechanical testing in the consumer goods industry determines product durability and safety, such as impact resistance for toys and fatigue resistance for home appliances, making it core to compliance and quality. UnitedTest can cover mechanical tests for all categories of consumer goods, including tensile, impact, and hardness tests, compatible with national and international standards, and offers customized testing solutions.

In the field of medical and biomedical sciences, mechanical testing determines the safety and compatibility of implanted devices and biomaterials, making it a core part of regulatory approval. UnitedTest can cover a full range of tests including tensile, fatigue, and wear tests, compatible with national and international standards, and provides customized biomechanical testing solutions.

Material strength is a course that most engineering fields are required to study in university education. This interesting course is very practical and makes use of testing equipment in the materials laboratory.

Mechanical testing of industrial products and components is essential to ensure their load-bearing, fatigue resistance, and impact resistance, directly preventing production accidents and ensuring stable operation of equipment. UnitedTest can cover a full range of tests including tensile, hardness, and fatigue, complying with national and international standards, and provides customized industrial mechanical testing solutions.

Mechanical testing in the plastic pipe industry determines ring stiffness, impact resistance, and tensile performance, directly preventing pipe bursts and deformation risks. UnitedTest can cover full-dimensional mechanical testing of pipes, complies with ISO,ASTM,EN et.c, international standards, and provides customized testing solutions.

In the construction engineering and building materials industry, mechanical testing determines the compressive and tensile properties of materials such as concrete and steel, which is core to ensuring the safety and durability of buildings. UnitedTest can cover the full range of building material mechanical tests, complies with ISO, ASTM international standards, and provides customized testing solutions for compressive, tensile, and other properties.

Mechanical testing in the food and beverage industry involves the compressive and tensile performance of packaging and the safety of food texture, directly ensuring storage, transportation safety, and the eating experience. UnitedTest can cover all-dimensional mechanical testing for packaging and food texture, comply with national and international standards, and provide customized testing solutions.

Mechanical testing in the packaging industry determines the packaging's resistance to compression, impact, and tension, directly ensuring the safety of contents during storage and transportation. UnitedTest can cover comprehensive mechanical testing for packaging, complying with ISO, ASTM Standards, and provides customized testing solutions for compression, drop, tear, and more.

Mechanical testing in the transportation industry concerns the load-bearing and fatigue resistance performance of core components such as vehicles, tracks, and containers, directly ensuring transport safety and equipment durability. UnitedTest can cover mechanical testing for all types of transportation materials, complying with national and international standards, and provides customized testing solutions including tensile, fatigue, and impact tests.

Metallurgical testing examines the properties of metallic materials to determine if a particular metal is appropriate for its intended use.

Testing of polymer materials covers mechanical, thermal, and chemical properties, verifying strength, heat resistance, composition, and ensuring product quality and compliance.

UnitedTest offer world-class testing solution in testing for polymeric materials, including elastomers, thermoplastics, composites, coatings, and structural adhesives in a variety of industries.

Testing of rubber and elastomers is used to assess the various properties and performance of materials under different conditions. This is crucial for ensuring the safety, functionality, and quality of rubber and elastomer products used in industries such as automotive, construction, consumer goods, and aerospace.

Conduct adhesive testing using various testing methods to determine their performance and characteristics in applications across multiple industries such as aerospace, automotive, construction, packaging, industrial, medical, and energy, thereby supporting application development and quality assurance.

UnitedTest supply machine and testing solution for tension, compression, fracture toughness, direct shear, triaxial and ultrasonic velocity are common concrete and rock testing applications.

UnitedTest has helped a number of companies involved in the wood, paper, cardboard, and corrugated industry with their testing needs. Our materials testing systems are capable of testing raw materials, components, and finished products.

UnitedTest testing system is trusted by leading medical device manufacturers, universities, and medical research laboratories worldwide. Whether testing tissues or bioresorbable materials, stents, or sutures, UnitedTest offers a variety of single-actuator and dual-actuator systems to meet your biomedical testing needs.

Mechanical testing in the textile fabric industry determines core properties such as fabric tensile strength, tear resistance, and wear resistance, directly affecting product durability and safety. UnitedTest can cover comprehensive mechanical tests for textiles, complying with national standards / ISO standards, and provides customized testing solutions including tensile, tear, and puncture tests.

The mechanical testing of industrial components directly determines the load-bearing, fatigue resistance, and wear resistance of the parts, helping to avoid equipment failure risks. UnitedTest can cover a full range of tests including tensile, hardness, and fatigue, is compatible with ISO/ASTM/GB standards, and provides customized mechanical testing solutions for industrial components.

Mechanical testing in the glass-ceramics industry determines core properties such as flexural strength, hardness, and fracture toughness, directly helping to avoid brittleness and failure risks. UnitedTest can cover comprehensive testing for flexural strength, hardness, and fracture toughness, compatible with national and ISO/ASTM standards, and provides customized testing solutions.

Tensile test evaluates material resistance to stretching, measuring strength/elongation critical for quality control. UnitedTest offers universal tensile testers (10-600KN) compliant with ASTM/ISO standards, providing tailored solutions for metals, polymers, medical & industrial materials.

Compression test assesses material resistance to compressive loads, measuring strength/deformation critical for quality validation. UnitedTest offers compression testing machines compliant with ASTM/ISO standards, providing tailored solutions for concrete, plastics, metals and industrial components.

Flexural & Bend tests evaluate material resistance to bending forces, measuring strength, stiffness and ductility for quality assurance. UnitedTest provides flexural testing machines (3-point/4-point bend) compliant with ASTM/ISO standards, offering tailored solutions for composites, plastics, metals and construction materials.

Torsion Test evaluates material resistance to rotational forces, measuring torsional strength/ductility critical for fasteners, insulators, shafts. UnitedTest offers torsion testers compliant with ASTM A938/ISO 16047, providing tailored solutions for automotive, aerospace, fastener industries.

Fatigue Test assesses material durability under cyclic loading, critical for predicting service life of industrial components. UnitedTest offers fatigue testing systems (axial/bending/torsion) compliant with ASTM E466/ISO 12106, providing tailored solutions for automotive, aerospace and manufacturing sectors.

Peel Test measures material adhesion strength by evaluating resistance to peeling forces, critical for adhesives, films, packaging. UnitedTest offers peel testers compliant with ASTM D903/ISO 8510, covering 90°/180° peel tests, and tailored solutions for packaging, automotive, textile industries.

Impact Test evaluates material resistance to sudden shock loads, critical for assessing toughness and fracture risk. UnitedTest offers impact testers (Charpy/Izod/fall weight) compliant with ASTM E23/ISO 148, providing tailored solutions for metals, plastics, glass and industrial components.

Tear & Shear Test evaluates material resistance to tearing and shearing forces, measuring critical strength parameters for quality control. Tear tests (Elmendorf/trouser/trapezoidal) assess resistance to crack propagation in films/fabrics, while shear tests measure resistance to parallel forces in joints/bolts. UnitedTest provides universal testing machines (10KN-600KN) with specialized fixtures for both tests, compliant with ASTM D624/D3164 and ISO standards, serving automotive, packaging and construction industries.

Hardness test measures material's resistance to permanent indentation, critical for quality control. UnitedTest offers universal hardness testers (Rockwell/Brinell/Vickers) compliant with ASTM/ISO standards, plus tailored hardness testing solutions for diverse industrial needs.

Biaxial/triaxial tests evaluate material performance under multi-axis loads, critical for biomaterials, metals and composites. UnitedTest provides compliant testing machines (ASTM/ISO) for planar biaxial, static/fatigue triaxial tests, with tailored solutions for industrial & biomedical needs.

Friction and wear tests assess material resistance to friction, abrasion and wear, critical for industrial material performance validation. UnitedTest offers tribometers compliant with ASTM G99/ISO standards, covering pin-on-disk, four-ball tests, and tailored friction & wear testing solutions for diverse industries.

Pressure test evaluates material/component resistance to static/dynamic pressure, critical for sealing, strength and safety validation. UnitedTest offers pressure testing machines compliant with ASTM/ISO standards, covering burst, hold-pressure tests, and tailored solutions for industrial, automotive & medical sectors.

Fire test assesses material flammability, heat resistance and fire-retardant performance, critical for safety compliance across industries. UnitedTest offers fire testing equipment compliant with ASTM/ISO/UL standards, providing tailored fire test solutions for building materials, plastics and industrial components.

Non-destructive Test (NDT) evaluates material/component integrity without damage, critical for safety & quality across industries. UnitedTest offers ultrasonic/X-ray/magnetic particle NDT equipment compliant with ASTM/ISO standards, plus tailored NDT solutions for aerospace, automotive & manufacturing sectors.

ASTM D2863 Oxygen Index Tester | Limiting Oxygen Index LOI Test | UnitedTest

ASTM D2863 standard determines plastic limiting oxygen index (LOI / OI), the minimum oxygen volume percentage required to sustain candle-like flaming combustion at ambient temperature. UnitedTest manufactures ASTM D2863 compliant oxygen index testers for polymer flame retardancy and fire safety testing.

ASTM D2863 is the widely adopted standard test method for measuring the minimum oxygen concentration needed to maintain candle-like flaming combustion of plastics, commonly known as Oxygen Index (OI) or Limiting Oxygen Index (LOI). The test calculates the minimum volume percent of oxygen within an oxygen‑nitrogen gas blend that can support steady flaming combustion of a specimen conditioned at 23 ± 2 °C. Simply put, this test evaluates how much oxygen plastic materials require to keep burning continuously.

A core benchmark for material evaluation: regular ambient air holds approximately 21% oxygen. If the measured OI ≤ 21%, the material will sustain combustion under normal air conditions; if OI > 21%, the material is self-extinguishing in ambient air, and a higher OI value represents stronger flame-retardant performance. This test is extensively used for flame retardant material R&D, quality control, fire classification and certification of polymers, plastics, rubber and composite materials. UnitedTest designs and produces high-precision ASTM D2863 oxygen index testing machines for material laboratories and industrial quality inspection.

Test principle

The test measures the minimum volume percentage of oxygen in a flowing oxygen-nitrogen mixture that will just sustain flaming combustion of a vertically oriented specimen. The principle is based on the observation that combustion requires a certain minimum oxygen concentration; below this threshold, the flame cannot propagate and will extinguish. By systematically varying the oxygen concentration and observing burning behavior, the critical oxygen level (oxygen index) is determined.

The oxygen index is calculated as: OI = [O₂ / (O₂ + N₂)] × 100%

where O₂ and N₂ represent the volumetric flow rates of oxygen and nitrogen, respectively.

Test Methods (Three Procedures)

Procedure A – Top Surface Ignition

- Ignition is applied only to the top surface of the specimen

- The flame is applied to the top edge until the entire top surface is burning

- Used for most rigid, self-supporting materials

- Most commonly used procedure for general flammability ranking

Procedure B – Propagating Ignition

- The flame is applied to the side of the specimen near the top

- Allows flame to propagate downward along the specimen

- Used when evaluating materials where flame spread is a primary concern

- More stringent ignition condition than Procedure A

Procedure C – Short Procedure (Pass/Fail)

- A simplified screening test

- Specimen is tested at a single specified oxygen concentration

- Determines whether the material meets or exceeds a minimum oxygen index requirement

- Used for quality control and compliance verification where a specific threshold must be met

Test Specimen Information

Type	Length (mm)	Width (mm)	Thickness (mm)	Material Form
I	80–150	10 ± 0.5	4 ± 0.25	Molded materials (bars)
II	80–150	6.5 ± 0.5	3.0 ± 0.5	General purpose bars
III	80–150	6.5 ± 0.5	1.5 ± 0.15	Thin rigid sheets
IV	140–150	52 ± 0.5	≤ 10.5	Thick sheets/boards
V	140–150	20 ± 0.5	≤ 10.5	Cellular materials (foam)
VI	80–150	20 ± 0.5	0.02–0.5	Flexible films and sheets

Test equipment required for ASTM D2863 Oxygen Index Test

Recommend UntiedTest YZS series Oxygen Index Tester/Limiting Oxygen Index (LOI) Test Machine, consist of below:

Combustion Column	Vertical, heat-resistant quartz glass cylinder Standard dimensions: ~75 mm inner diameter, ~450 mm height Glass beads (≈4.5 mm diameter) at the bottom to ensure uniform gas mixing Gas inlet at the bottom, open at the top
Gas Control and Measurement System	Separate oxygen and nitrogen supply lines (purity ≥ 98%) Precision mass flow controllers or rotameters for each gas Pressure gauges and needle valves for flow regulation Oxygen concentration measurement resolution: ±0.1% Typical flow rate range: 1.0–15.0 L/min per gas
Specimen Holder	Clamp assembly positioned centrally in the column Two sets of clamps: one for rigid self-supporting materials, one for flexible films/sheets Holds specimen vertically with top end at specified height
Ignition System	Handheld propane burner with 2.0 mm diameter copper tube nozzle Flame length adjustable to 16 ± 4 mm Electronic ignition option available on modern instruments

Key Test Parameters

Specimen orientation	Vertical, centred in chimney
Gas mixture	Oxygen + nitrogen, flowing upward
Gas velocity	40 ± 2 mm/s at 23 ± 2 °C
O₂ measurement accuracy	± 0.5 % by volume
O₂ adjustment precision	± 0.1 % by volume
Gas temperature	23 ± 2 °C entering the chimney
Apparatus ambient	23 ± 5 °C
Conditioning	≥ 40 h at 23 ± 2 °C and 50 ± 5 % RH per Practice D618; test within 30 min of removal from the conditioning enclosure
Ignition time	Up to 30 s maximum (igniter withdrawn every 5 s to check for sustained burning)
Igniter flame height	16 ± 4 mm
Burning-time criterion	180 s
Burnt-length criterion	50 mm from the ignited end
Concentration step (d)	Typically 0.2 %

1. Gas flow stabilization: The gas mixture must flow for at least 30 seconds before ignition to stabilize concentration

2. Ignition technique: Flame applied without disturbing gas flow; burner removed promptly after ignition

3. Burning criteria: A specimen is considered to "burn" if it sustains flaming for at least 3 minutes or burns past the 50 mm mark

Test procedure of ASTM D2863 Oxygen Index Test

Prepare specimens — cut/mold to the specified type and dimensions; mark reference lines per the chosen procedure.
Condition — ≥ 40 h at 23 ± 2 °C, 50 ± 5 % RH.
Calibrate the gas measurement/control system.
Install the specimen vertically in the holder at the chimney centre.
Set gas flow — adjust oxygen/nitrogen to the target concentration at 40 ± 2 mm/s.
Ignite the top of the specimen with the standard flame (≤ 30 s).
Observe — record whether burning exceeds 180 s or the 50 mm mark (X or O).
Adjust — lower O₂ if "X", raise O₂ if "O", by the step size d.
Repeat across a series of specimens until the up-and-down sequence is complete.
Calculate OI via Dixon's up-and-down formula (OI = C_F + k·d) and estimate the standard deviation.

Industry Application Fields

Materials covered:

Structurally self-supporting vertical bars or sheet up to 10.5 mm thick — solid, laminated, or cellular materials with apparent density > 15 kg/m³
Flexible sheet or film tested while vertically supported
In some cases, cellular materials with apparent density < 15 kg/m³

Industry sectors:

Plastics & polymer compounding — flame-retardancy QC for ABS, PC, PVC, polyolefins, polyamides, polyesters, engineering polymers
Wire & cable — insulation and jacketing compounds (PVC, XLPE, PE), LSZH (low-smoke zero-halogen) and fire-resistant cable formulations
Electrical & electronics — enclosures and housings where short-circuit/overheat fire risk matters
Building & construction — insulation foams (PU, EPS, XPS, polyisocyanurate), profiles, sealants, geomembranes, roofing
Transportation interiors — aerospace, rail, automotive, marine
Textiles & fibers — technical textiles, protective workwear, upholstery, carpets
Films & flexible packaging — polymer films, multi-layer laminates, agricultural films
Rubber & elastomers — vulcanized rubber, TPEs, sealing compounds
Flame-retardant additive R&D — evaluating brominated, phosphorus, mineral-filler (ATH/MDH), and intumescent systems

Related Test Standard:

ISO 4589-2	Plastics - Determination of burning behaviour by oxygen index - Part 2: Ambient-temperature test
ASTM D2863	Standard Test Method for Measuring the Minimum Oxygen Concentration to Support Candle-Like Combustion of Plastics (Oxygen Index)
GB/T 2406.2	Plastics.Determination of burning behaviour by oxygen index.Part 2:Ambient-temperature test
GB/T 5454	Textiles--Burning behaviour--Oxygen index method
ISO 4589-3	Plastics - Determination of burning behaviour by oxygen index - Part 3: Elevated-temperature test
GB/T 2406.3	Plastics—Determination of burning behaviour by oxygen index—Part 3: Elevated-temperature test
IEC 61144	Test method for the determination of oxygen index of insulating liquids
GB/T 16581	Test method for the determination of oxygen index of insulating liquids
ISO 3582	Horizontal flammability test for flexible cellular polymers
NES 714	Commonly used alongside for LOI determination (UK Naval Engineering Standard)

Why ASTM D2863 Oxygen Index Test is Important for Polymeric Materials

It converts "flame retardancy" into a single, objective, quantitative number. Rather than a subjective description, you get one reproducible figure (e.g., OI = 26.8) that can be tracked, specified, and audited.

The 21 % threshold is physically meaningful. Because air is ~21 % oxygen, the OI directly answers the practical question: will this material sustain a flame in a real room? This makes it uniquely intuitive for specification writing.

It is fast, cheap, and uses tiny specimens. It is described as the most economical and precise quality-control test for combustible materials available to modern labs. This makes it ideal for high-volume batch QC and rapid R&D iteration.

It is highly sensitive to flame-retardant formulation. It is the primary tool for screening flame-retardant additives and optimising loading levels during compound development — you can see the effect of adding, say, mineral filler ATH/MDH or a phosphorus FR within a couple of percentage points.

It enables reliable comparative ranking. Different polymers, grades, or formulations can be ranked by flammability on a common scale, guiding material selection.

It feeds regulatory, safety, and certification pathways. Widely used for building-code, aerospace, rail, marine, and electrical-product flame-retardancy compliance.

Keywords: ASTM D2863 oxygen index tester,limiting oxygen index LOI test machine,plastic oxygen index test equipment,polymer flame retardancy analyzer,plastic candle-like combustion tester,ambient temperature oxygen index test rig,fire safety test machine for plastics,plastic flammability tester,polymer combustion performance tester,flame retardant material testing instrument,lab oxygen index analyzer,plastic fire resistance test equipment,rubber composite oxygen index tester,material flammability certification test machine,ASTM D2863 flammability test instrument

ISO 4589‑2 LOI test apparatus is widely used for flammability testing of plastics, polymer compounds, rubber, rigid & flexible foam materials, cable‑insulation materials, composite laminates, thin packaging films, automotive‑interior plastics, building‑decorative polymer materials, E&E component plastics.

Oxygen Index Apparatus/LOI tester (Limitation Oxygen Index tester) is widely used to measure burning performance of plastics, rubber, fiber, foam,,film etc., The technique measures the minimum percentage of oxygen in the test atmosphere that is required to marginally support combustion.

High-temperature limit oxygen index tester refers to the volume fraction concentration of oxygen that can support the combustion of materials in a mixture of oxygen and nitrogen gas, and is an index that characterizes the combustion behavior of materials.

Q1. What is ASTM D2863?

ASTM D2863 is an ASTM International fire-test-response standard titled "Standard Test Method for Measuring the Minimum Oxygen Concentration to Support Candle-Like Combustion of Plastics (Oxygen Index)." It is maintained by ASTM Committee D20 on Plastics, Subcommittee D20.30 on Thermal Properties, and has been approved for use by agencies of the U.S. Department of Defense.

Q2. What is the Oxygen Index (OI / LOI)?

The Oxygen Index is the minimum concentration of oxygen, expressed as volume percent, in a flowing mixture of oxygen and nitrogen that will just support flaming combustion of a material initially at 23 ± 2 °C under the conditions of this test method. It is also widely called the Limiting Oxygen Index (LOI).

Q3. Why is the number 21 % so important in this test?

Because ambient air contains approximately 21 % oxygen. That makes the OI directly readable in real-world terms:

OI < 21 % — normal air supplies more than enough oxygen; the material will continue to burn once ignited (readily combustible).
OI ≈ 21–27 % — marginal / slow-burning; tends to self-extinguish in still air, but the safety margin is thin.
OI > 27–28 % — generally regarded as self-extinguishing / genuinely flame-retardant. High-risk sectors such as aerospace and rail often specify OI > 28 %.

Q4. Is OI the same as "fire rating"?

No. OI is a quantitative flammability index, not a fire rating or fire-resistance classification. The standard itself states (§1.7) that it does not incorporate all factors required for fire hazard or fire risk assessment, and (§5.2) that correlation with burning characteristics under actual use conditions is not implied.

Q5. Why is ASTM D2863 important for a material?

Five practical reasons:

It turns flame retardancy into one objective number. Instead of a subjective description, you get a reproducible figure (e.g., OI = 26.8) that can be written into a spec, tracked over time, and audited.
The 21 % benchmark is physically meaningful. It answers the practical question: will this material sustain a flame in a normal room?
It is fast, cheap and uses tiny specimens. It is widely regarded as the most economical and precise quality-control test available for combustible materials — ideal for high-volume batch QC and rapid R&D iteration.
It is highly sensitive to flame-retardant formulation. It is the primary screening tool for FR additives — you can see the effect of changing a mineral filler (ATH/MDH), phosphorus, or intumescent loading within a couple of OI points.
It feeds certification and compliance. LOI data is a foundational input to flame-retardancy compliance programmes in building, cable, aerospace, rail, marine and electrical products.

Q6. Who actually uses OI data?

Plastics and polymer compounders, wire & cable makers (PVC, XLPE, PE, LSZH compounds), electrical/electronics enclosure producers, building-insulation foam makers, rubber and elastomer producers, textile and technical-fabric mills, film and flexible-packaging converters, aerospace/rail/automotive interior suppliers, FR-additive developers, universities and third-party certification labs.

Q7. Can OI alone predict real-fire behaviour?

No. ASTM D2863 measures downward, candle-like burning of one small bar in a quiet chamber — with no external radiant heat, no realistic ventilation, and no accounting for dripping, smoke toxicity or heat-release rate. Real fires, and the codes written for them, care about those things. Use OI to rank and screen, then qualify the final material to the code test that governs your application (UL 94, cone calorimetry, IEC 60332, EN 45545-2, etc.).

Q8. How are flexible and thin films prepared?

Type V (flexible sheet): clamped by both vertical edges in a frame carrying reference marks 20 mm and 100 mm below the frame top.
Type VI (thin film): insert one corner into the slit of the rolling tool and wind the film around the rod in a 45° spiral, tape the last end while still on the rod, pull the rod out, then cut the roll 20 mm from the top end.

Q9. Can I compare results across different specimen types?

Only with care. The standard restricts comparison: results from Type III, V and VI may be compared only with results from specimens of the same form and thickness.

Q10. How does the step size affect uncertainty?

Maximum OI uncertainty ≈ 0.54 at d = 0.2, and ≈ 0.66 at d = 0.4. Smaller steps give tighter results but require more specimens and time.

Q11. What should a test report include?

OI value; specimen type and dimensions; gas measurement/control device accuracy; procedure used (A, B or C); for Procedure C, the specified minimum OI and whether the material was above or below it; estimated standard deviation and concentration increment if other than 0.2 %; observed behaviour (charring, dripping, severe shrinkage, erratic burning, afterglow); and any deviations from the method.

Q12. What are common causes of scattered or unreliable results?

Inconsistent specimen preparation (dimensional deviation, edge burrs, surface contamination); inadequate conditioning (especially for hygroscopic materials); incorrect gas flow velocity; ignition time too short or too long; specimen not vertical; and operator subjectivity in judging the burn/no-burn response. Dripping that ignites cotton wool below is always recorded and can dominate the result.

Q13. Does specimen thickness change the OI?

Yes, significantly. Thicker specimens dissipate heat less readily and tend to give lower OI; thinner specimens cool faster and tend to give higher OI. Always test at the standard thickness and compare like with like.

Q14. Is ASTM D2863 the same as ISO 4589-2?

They are technically equivalent in principle and apparatus when direct oxygen-concentration measurement (§6.3.1) is used. Both define Procedure A (top surface ignition), Procedure B (propagating ignition) and a short procedure. Watch the details: ASTM D2863 states a cellular-density threshold of 15 kg/m³ (vs 100 kg/m³ in ISO), and there are minor differences in specimen sizes and gas-flow control. Always test to the standard named by your customer or regulation.

Q15. How does ASTM D2863 differ from UL 94?

They are complementary, not interchangeable:

	ASTM D2863 (LOI)	UL 94
Result type	Quantitative — a number (e.g. 28 %)	Qualitative — a class (V-0, V-1, V-2, HB)
What it measures	Minimum oxygen needed to sustain combustion	Extinguishing and dripping behaviour in air
Typical use	R&D, formulation screening, QC	Final product certification

A high OI does not guarantee UL 94 V-0, and a V-0 material is not guaranteed a high OI. Published comparisons find only limited, inconsistent correlation between these methods and full-scale fire behaviour. Practically: LOI < 28 % makes V-0 unlikely; LOI ≥ 30 % is a useful screening indicator but not a guarantee.

Q16: Why Choose UnitedTest as Your Oxygen Index Tester Supplier?

UnitedTest – Leading Manufacturer of ASTM D2863 Oxygen Index Test Equipment

UnitedTest is a professional manufacturer and supplier of high-precision **ASTM D2863 oxygen index test equipment**, also known as limiting oxygen index (LOI) testers. With years of expertise in flammability testing instrumentation, UnitedTest designs and produces advanced oxygen index testing machines that fully comply with ASTM D2863, ISO 4589-2, GB/T 2406, and other international standards.

Our oxygen index tester series delivers exceptional accuracy, reliability, and ease of use for plastics testing laboratories, R&D centers, quality control departments, and third-party testing institutions worldwide.

UnitedTest stands out among oxygen index test machine manufacturers for our commitment to quality, precision, and customer support:

Expert Technical Support – Our team of flammability testing specialists provides installation guidance, calibration services, and ASTM D2863 standard training
Customization Capability – We offer tailored solutions for specific testing requirements, including elevated temperature options and automated testing configurations
Global Distribution Network – Fast worldwide shipping with professional on-site installation and training services available
Competitive Pricing – Direct factory pricing without compromising on quality or performance
Comprehensive After-Sales Service – Warranty coverage, spare parts availability, and ongoing technical assistance

We offer customization to meet your specific needs. Our expert team will collaborate with you to develop the perfect product for you

ASTM D2863 Oxygen Index Test — LOI Testing for Plastics, Rubber, Foam & Film