The monograph is devoted to the development of methods and systems of non-destructive testing and technical diagnostics of the thermophysical properties of building materials and products. Physico-mathematical models of temperature fields in the studied objects with contact and contactless thermal influence from a linear, disk or point heat source are presented, adequately describing the thermal processes in controlled products. A mathematical description of the ordered thermal regime on the surface of the samples under their symmetric heating or cooling has been developed. The analysis of errors in the results of measurements of the developed methods and the measuring systems implementing them is given. The monograph is intended for scientific, engineering and technical workers, university teachers, graduate students, students