The document applies to earthworks and foundation engineering. The particle density is an aid to determining the water content of the pores by means of immersion weighing or an air pycnomter, to determining the shrinkage limit and the particle size distribution of soil samples by sedimentation analysis. It is also used to evaluate the results of the proctor test. The particle density determined using the capillary pycnometer is a suitable means of establishing the pore content of most soils. Teh wide-mouth pycnometer method is preferable for soils with a very low pore content.#,,#