Modelling of heat conduction calorimeters. Case of a non-differential skin calorimeter

• Three non-differential skin calorimeters were modeled and validated. • The model includes ambient and thermostat temperature effects on heat flux. • The device can measure skin heat flux, heat capacity, and thermal resistance. • The skin calorimeter is able to estimate the internal core temperature. In non-differential calorimeters, the ambient temperature, the thermostat temperature, and the thermostat cooling system affect the measured heat flux. For this reason, the modelling and calibration procedures should take into account all the variables that affect the heat flux transmitted through the calorimeter. In this work, we present the complete calibration of three non-differential skin calorimeters designed to measure the heat flux, the heat capacity and the thermal resistance of a localized skin surface. In addition, the incorporation of the skin into the calorimetric model allows the determination of the core temperature of the tissue where the measurement is performed. The electrical calibration is validated with measurements with the three calorimeters on the volar and dorsal areas of the wrist of a healthy 30-year-old male subject.