Auto-ignition temperature measurement
The auto-ignition temperature (or self-ignition) of a compound is the temperature from which it ignites spontaneously in air. It should not be confused with the ignition temperature, nor with the flash point, where an ignition source (flame, spark, etc.) is necessary for ignition.
How is the auto-ignition temperature measured?
The autoignition temperature is generally measured according to a method developed from standard ASTM E659 – Standard test Method for Autoignition Temperature of Chemicals. The compound is placed in a reactor under an atmosphere containing air at controlled pressure and temperature. Ignition is detected by observing a rise in reactor temperature and pressure. Successive tests are carried out in order to frame the lowest temperature at which self-ignition takes place.