In geotechnical engineering, there is a need for a technique to measure in-place density and water content of soil quickly, precisely, and preferably, in a non-destructive manner. Combined traditional electric and electromagnetic methods could answer to this need : they are used in this study to determine the relationships of electrical conductivity and dielectrical permittivity versus hydric properties of loamy sand on a density and moisture controlled site. This plurimetric experimental site is composed of three basins of the same material. Each basin is at one soil water content and composed of several parts compacted at different dry densities. Previous laboratory studies showed that electrical conductivity and dielectrical permittivity increase with the increase of dry density and with the increase of gravimetric water content. The aim of this study is to compare laboratory and in-situ measurement data in order to obtain a model useable on site.