Introduction to Unit of Measurement and System of Units
Each model has a basic system of unit to ensure that all material properties of that model are consistently measured and defined. All models are defined on the basis of system of units. A part can have only one system of unit.
Following are the types of quantities which govern the definition of unit of measurement:
• Basic Quantities—The basic units and dimensions of the system of units. For example, consider the Centimeter Gram Second (CGS) system of unit. The basic quantity for this system of unit is:
◦ Length—cm
◦ Mass—g
◦ Force—dyne
◦ Time—sec
◦ Temperature—K
• Derived Quantities—The derived units are those that are derived from the basic quantities. For example, consider the Centimeter Gram Second (CGS) system of unit. The derived quantities for this system of unit are as follows:
◦ Area—cm^2
◦ Volume—cm^3
◦ Velocity—cm/sec