Measuring the Minimum Oxygen Concentration to Support Candle-Like Combustion of Plastics (Oxygen Index) ASTM D2863
ASTM D2863 is a method to determine the minimum concentration of oxygen in an oxygen/nitrogen mixture that will support a flaming burn in a plastic specimen. There is no correlation to real end use conditions.
The test sample is positioned vertically in a glass chimney, and an oxygen/nitrogen environment is established with a flow from the bottom of the chimney. The top edge of the test sample is ignited, and the oxygen concentration in the flow is decreased until the flame is no longer supported.
There are 6 specifications for the test specimen depending on the type of material being tested. For injection molded samples, 80 to 150 mm long by 10 mm wide by 4 mm thick is the recommended size. Results for different materials should only be compared if the testing was done on samples of similar size.
Oxygen Index, in percent, is calculated from the final oxygen concentrations tested. The test results relate only to the behavior of the test specimens under the conditions of this test method and the results must not be used to infer the fire hazards of the material in other forms or under other fire conditions.
**Please note that this test description is intentionally generic in nature and aimed at providing a descriptive summary to enhance test understanding. Standards can be obtained from appropriate standard authorities.
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