Comparison of three methods for determining the particle density of soil with liquid pycnometers

Three liquid pycnometer methods for determining the particle density of a sand and peat soil were assessed. The determinations were made on samples at two initial water contents, air dry and slightly moistened. Water was used as the filling liquid in methods 1 and 2, and ethanol in method 3. In method 1, a water bath was used to wet the samples while a 70 kPa vacuum was used in methods 2 and 3. The mean values determined with the methods tested differed by less than 0.15 g/cm3. It was concluded that the most precise and accurate values can be achieved using water as the filling liquid and a water bath to wet the samples.