MINIMUM IGNITION TEMPERATURE (MIT)
BS EN 50281-2-1 / ASTM E1491
The Minimum Ignition Temperature (MIT) test is conducted to determine the lowest temperature at which a hot surface will ignite a powder when dispersed in air, as a dust cloud.
Working through a range of powder concentrations, the material is dispersed through a heated vertical ‘Godbert-Greenwald’ furnace using compressed air. Once an ignition temperature is observed the furnace temperature is reduced, the dispersion pressure and powder concentration varied until the minimum ignition temperature is established.
MIT test is one of the three core tests for accessing a materials ignition sensitivity, particularly where ‘Avoidance of Ignition Sources’ is the ‘Basis of Safety’ for the operation. The data is required for defining the maximum operating temperature for electrical and non-electrical equipment used in areas where the test material is present.
Avoidance of Ignition Sources as a Basis of Safety, is often used for processes such as charging vessels from sacks, IBC’s or FIBC’s, pneumatic conveying, milling and tabletting operations to name a few. Many materials, that can create a flammable atmosphere, are found to be insensitive to ignition and therefore it is easy, practical and cost affective to ensure an ignition source capable of initiating a reaction is not present.
Related testing for ‘Avoidance of Ignition Sources’ are Minimum Ignition Energy (MIE), Layer Ignition Temperature (LIT) and Electrostatic testing.