Volume 39, Issue 3 (May 2011)
A Pilot Study on Thermal and Moisture Mapping of the Head-Helmet System Using Micro-Sensor Technology
To study the thermal comfort of any helmet, it is important to measure micro-climate parameters quantitatively within the helmet and link them to human perception. The micro-climate in helmet is usually assessed in terms of temperature and relative humidity (RH). Historically, due to limitations of test equipment, measurements have mainly addressed the temperature in a few locations and temperature/RH within thermal manikins. In this study, a new test rig was developed to measure multi-point temperature and RH inside a helmet while a human subject wearing it using micro-sensors. Altogether, 13 micro-sensors were embedded in a cricket helmet with the sensor facing towards the head. Two sensors were used to record ambient conditions. Real time display on a laptop was set to monitor the recording process. Using the rig developed, two types of cricket helmets were tested, each with three subjects for this study. Both thermal and moisture mapping were obtained, which may be the first time temperature and RH distributions within the air pocket between the helmet and the human subject have been reported. There are interesting relationships that existed between the temperature and RH distributions and the subjective perception. The test rig also has promise for thermal comfort studies of other products.