A method for dynamic measurement of the resistance to dry heat exchange by footwear.
Five different types of cold protective footwear have been tested with regard to their resistance to dry heat loss (i.e. the insulation) with a new electrically heated foot model. The model is able to simulate 'walking' movements in order to provide a more realistic simulation of wear conditions. Thermal insulation of shoes with and without a steel toe cap was the same. The insulating properties during simulated walking movements were 10-25% lower compared with static conditions. For two of the shoe models a significantly lower insulation value for the sole area was obtained when adding a weight of 30 kg. A significant difference could also be found between the insulation values of two different sizes of one of the models. Measurements with the standard method (EN 344) correlated well with the local insulation value of the sole part of the thermal foot. Correlation with the insulation value for the whole shoe was much less, variation was bigger and ranking in terms of cold protection differed between methods. The electrically heated foot model appears to provide a reproducible, accurate and more realistic method for measuring the insulation properties of shoes than EN 344.
Bergquist
K
K
Division of Industrial Ergonomics, Luleå University, Sweden.
Holmér
I
I
D000704:Analysis of Variance; D001833:Body Temperature Regulation / Q000502:physiology*; D003081:Cold Climate; D006804:Ergonomics / Q000379:methods*; D006801:Humans; D008348:Manikins; D016273:Occupational Exposure / Q000517:prevention & control*; D011481:Protective Clothing; D012775:Shoes; D016138:Walking / Q000502:physiology