ISO 12988-2:2004 describes a test method for the thermogravimetric (TGA) determination of CO₂ reactivities and dusting of shaped carbon anodes used in the aluminium reduction industry. Many types of apparatus are available with a wide variety of thermal conditions, sample-size capability, materials of construction and procedures for determining the mass loss and subsequent rate of reaction. This test method standardizes the variables of sample dimensions, reaction temperature, gas velocity over the exposed surfaces, and reaction time such that results obtained on different types of apparatus are correlatable.