Isothermal Differential Calorimetry as a means to measure insulation aging rate down to the operating temperatures

Isothermal differential calorimetry makes it possible to measure aging reaction rate down to service temperatures. The reactions taking place in the aging processes can be separated by using appropriate gas mixtures for test atmospheres. Reaction rate curves do not give an easy solution to the extrapolation problem of the life test results, because the reaction rate curves may be atmosphere dependent, pre-aging time dependent and pre-aging temperature dependent. For further investigation of the extrapolation problem, conventional life tests should be conducted in the same controlled atmospheres as the reaction rate measurements. The effects of the different aging reactions on the useful lives of insulating materials could then be estimated.