2 Autogenous ignition temperature (AIT) in high
For testing, solid materials are divided and liquids are applied onto ceramic fibers.
A sample tube that contains a sample mass of ca. 0.1 g to 0.5 g is placed into an
autoclave of 34 cm3 in volume. A low-frequency heater allows to heat the sample
inductively in an almost linear way at a rate of 110 °C/min.
A thermocouple on the bottom of the sample tube measures the temperature. The
pressure is measured by means of a pressure transducer.
The ignition of the sample can be recognized by a sudden rise in temperature and
Usually, the maximum use temperature of the sample is fixed at a value that is
100 °C below the determined AIT. This safety margin considers the fact, that the
AIT is not a constant and depends on test method, sample preparation, and other
parameters. Publications in literature as well as researches in BAM confirm this fact.
The safety margin of 100 °C has been proven over many decades. For use temperatures
up to 60 °C, and depending on the intended purpose, BAM only performs
oxygen impact tests (test method 1) or flange tests (test method 4).