Overall Uncertainties of Human Thermoregulation Studies

This paper presents the quantified effects of uncertainties and errors relating to typical human thermoregulatory experiments involving liquid cooled garments in suit calorimeters. It reports on-going efforts to develop a state-of-the art facility to perform human thermal testing for space suit thermal comfort control. A systematic methodology using sensitivity derivatives combined with instrument uncertainties is applied to develop a bound of accuracy on measured experimental variables. As for unmeasured experimental variables, methods used to estimate and minimize these uncertainties are also included. During actual experimentation with human subjects, the variability in experiments associated with subjects is modeled; steps taken to minimize errors and ensure repeatability are also reported. Results from this analysis will suggest specific improvements to the experimental setup in the most effective manner from the experimental accuracy and cost standpoint. Methods developed in this paper are applicable to any experimental facility with differentiable system equations to quantify its uncertainty and identify the most effective improvements for the facility.