| 摘要 |
A flammability tester for samples in the milligram range. A tube with a lower pyrolyzing region, or pyrolyzer, contains a sample that is heated to thermally degrade in the absence of oxygen, or pyrolyzed, to produce fuel gases. An inert gas carries the fuel gases to an upper combustion region, or combustor, where oxygen is measured into the gas flow containing the inert gas and fuel gases. Combustion of the fuel gases occurs at a temperature where the reaction time for almost all of the fuel gases is at or below 10 seconds. Under these conditions, the combustor volume need for complete combustion is small, permitting the fuel gases to be oxidized as they are liberated and travel from the pyrolyzer into the combustor in what is essentially sequential flow. Complete combustion in such a small volume produces a large decrease in the oxygen content of the gases emerging from the combustor, allowing the use of a simple inexpensive oxygen analyzer to measure the oxygen content of the gases emerging from the combustor. Oxygen depletion can be used to determine flammability parameters of the sample. The tester can be fitted with a thermometer to measure the combustion temperature of the pyrolyzed sample. The tester may also be configured to use a carbon dioxide analyzer to measure additional flammability parameters. The tester may also be combined with a separate thermogravimetric analyzer to yield further flammability parameters where the mass loss rate of the pyrolyzing sample is needed.
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