Light transmittance through dry, sieved sand: some test results

Abstract

A series of measurements was made at different light wavelengths of transmittance through various thicknesses of dry sand grains from a variety of size classes. Transmittance was found to decrease approximately exponentially with increasing sand layer thickness and with decreasing grain size. Transmittance did not vary significantly with incident light wavelength. It is concluded that for any dry sand, a layer with a thickness of 7 mm, and possibly much less, is capable of reducing the transmittance of incident light to 0.05 % or less. This result should be considered when collecting a surface sample as a modern analogue for a sample to be optically dated.