Lab report

Introduction : specific gravity, is the ratio of the weight of a given volume of a substance (density) to the weight of an equal volume of some reference substance, or, equivalently, the ratio of the masses of equal volumes of the two substances.The mentioned two substances usually mean water and soil .In addition, specific gravity test can identify solids (which will be used to assist in the hydrometer-analysis test) and to calculate the zero-air-voids curve for compaction results. The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved Discussion: Specific Gravity (Gs) is the second most important parameter in soil mechanics. It is the ratio of the unit weight (or density) of soil solids to the unit weight (or density) of water .Removing the air voids from the Pycnometer will be helpful to characterize the total density perfectly well.Otherwise, the air voids will affect on the total volume of the Pycnometer which will lead to an error of taking the authentic density . The temperature of water may have an obvious effect on the performance of pycnometer’s gas.Consequently, the test should be conducted within the specified operating temperature range of the apparatus.