A trace gas technique for measuring clothing microclimate air exchange rates

Crockford, G. W., Crowder, M., and Prestidge, S. P. (1972).Brit. J. industr. Med.,29, 378-386. A trace gas technique for measuring clothing microclimate air exchange rates. The rate at which clothing microclimate air is exchanged for ambient air influences the sensible and insensible heat loss from the microclimate. Factors which influence this air exchange are clothing permeability, wind speed, body movements, clothing design, and fabric properties. The influence of the first four factors has been studied using a trace gas technique for measuring the rate at which microclimate air is exchanged for ambient air. The trace gas technique and the mathematical model describing the loss of the trace gas from the microclimate are described. The technique is shown to have a high resolving power, enabling small changes in the four factors studied to be identified, and as the method is also very quick detailed studies of garment design can be made.