The complex of works on the diagnostics of changes in the material properties due to aging includes accelerated climatic tests (ACT) and performance tests before and after ACT. Along with the use of various methods for diagnosing defects that arise and develop during aging, it is also important to determine the changes in the thermophysical, moisture-physical and other properties of materials that have passed long-term operation associated with the processes of changes in the material structure. In addition to the method of synchronous analysis of changes in the thermophysical and moisture-physical properties of materials due to aging and corresponding corrections to changes in the heat and humidity conditions of products during long periods of operation and storage, an experimental facility and a method for experimental and analytical determination of the thermophysical properties of materials at variable heating rates based on the results of thermal tests of samples that have passed and have not passed ACT, using the approximation-superposition method in the analysis of test results to solve the inverse problem of thermal conductivity.