The guideline covers heat and cold insulation of pipes, channels, vessels, apparatus and machines as well as at cold-storage depots. Subject matter are the technical basics for measuring determination procedures for evaluation and verification of thermo-technical properties, e.g. heat flow densities and surface temperatures, stipulated by contract of insulation systems in the industry and the building services. Additionally, procedures for the determination of total heat losses are proposed. The total heat loss is of importance for the determination of the energy efficiency of operational installations.