Study on Evaluation Method of Spectral Reflectance and Transmittance of Clothing in the Visible and Near Infrared Ranges

Abstract

Near-infrared reflectance ρcl-NIR, visible reflectance ρcl-V, near-infrared transmittance τcl-NIR and visible transmittance τcl-V of 100% polyester and 100% cotton T-shirts and 40%polyester/60%cotton trouser were measured by using albedometer and pyranometer covered by IR-80 filters. Mean values of the ρcl-NIR, τcl-NIR and αcl-NIR were around 0.56, 0.31 and 0.13 respectively. Solar operative temperature considering net near-infrared and visible absorptances was derived. The effect of no near-infrared transmission of the clothing on predicted mean skin temperature decrease was approximately equal to that of the change of color on predicted mean skin temperature decrease in an outdoor environment.