At the German Institutes of Textile and Fiber Research Denkendorf (DITF), Denkendorf/Germany, a heat balance measuring tool (HBMT) has been developed that imitates heat and humidity transfer via the human skin. This allows heat and humidity exchange to be determined experimentally.
Heat output and exchange are different during sleeping than during participation in sports. The measuring device developed at DITF is thus concerned less with testing under standard conditions, and more with reconstructing realistic physical activities and climatic conditions.
Both electrical heat output and skin temperature can be variably specified as control variables for various physical activities and maintained at a constant level for the defined environmental climate, as well as the ambient climate of temperature and humidity.
The temperature of the measuring surface imitates skin temperatures and can in practice be variably specified between 22°C (environmental temperature) and 44°C (protein denaturation temperature).