Soft X‒ray digital radiography for soil structure: “area density of soil” of fi ne sand, silt and clay

Abstract

In this paper, authors proposed "Area Den-sity of Soil" （ADoS） which was a new concept for soil structure. ADoS was defined as weight of the solid phase per unit area. In addition, authors investigated how to measure ADoS by using Soft X‒ray Digital Ra-diography （SXDR）. Increase of specimen thickness and dry bulk density increased gray level of pixels in soft X‒ray digital image. Increase of ADoS also in-creased average of gray level of pixels in the image. The approximate expression to estimate ADoS from average of gray level of pixels in the image was a lin-ear function. The values calculated by the function were fit in ones measured. This fact provided us a measuring technique of ADoS by using SXDR.