SI Conversion

Abstract

This paper assists engineers in the conversion of the complicated foot‐pound‐second (FPS) system to the simplified System International (SI), expressed in meters‐newtons‐seconds. It is useful in both analytical and dimensional domains. A short history of the methods is given for general information. The masses of some elements, compounds, liquids, and gases are given, and are expressed in “dimensionless” units as ratios of their unit mass densities, and those of the unit mass density of water, which equal unity. Eight examples are given, showing the precise method of conversion. The examples also provide analyses to be used for checking the answers to the problems. This method of conversion will help engineers acquire the skill of its application, and also will provide a basis for checking and controlling the creation of formulas that are elaborated upon in the analytical and dimension domains. Furthermore, a new parameter of solidity is also introduced as a ratio of the volume of solids to that of the total unit volume. Solidity is inversely proportional to porosity.