"Units And Systems Of Measurement Their Origin, Development, And Present Status".pdf

The National Institute of Standards and Technology (NIST) was established in 1901 to provide fundamental measurement standards for science and industry. NIST conducts research and development in physics, mathematics, chemistry, and engineering, and is responsible for maintaining primary standards for length and mass. The institute provides information on units of measurement, including their definitions and equivalents. The subject of measurement systems and units can be treated from different standpoints, including scientific, engineering, and everyday applications. A unit is a special quantity in terms of which other quantities are expressed, while a standard is a physical realization or representation of a unit. The origin and development of units and standards date back to early societies, which used parts of the body and natural surroundings for measuring instruments. Early measurement systems included the Babylonian, Egyptian, and Roman systems, and units such as the cubit, foot, and yard were used to measure length. The point, a unit for measuring print type, was introduced in the 18th century. Units of measurement have evolved over time due to various modifying influences, and have been modified and grouped into different measurement systems.