New calibration method for skin calorimeters without baseline correction for continuous heat flux measurement

Abstract In this study, we present a new calibration method for a skin calorimeter that allows continuous measurement on the skin without the need for baseline correction. This approach is essential for practical applications that require immediate and uninterrupted monitoring, such as in clinical and physiological studies. The skin calorimeter, designed to measure heat flux, heat capacity, and thermal resistance of a 2 × 2 cm 2 skin area, is calibrated using a small aluminum block with a built-in resistor and temperature sensor. Calibration was performed over a range of thermostat temperatures (26–32 ºC) and Peltier currents (25, 75, and 125 mA), resulting in an accurate model, with a root mean square error (RMSE) of less than 0.15 mW in power measurements. The calorimeter's performance was validated through experiments on human subjects, demonstrating accurate and reliable heat flux measurements without baseline correction. This method simplifies the measurement process and enhances the practical utility of skin calorimetry in various applications.