Because of the increasing international use of the SI system (International System of Units) in medicine, the Committee on Hospital Care has written this statement to familiarize pediatricians with this concept. The current state of the system, its derivation, purported advantages, and controversial aspects are described; and the Committee has made specific recommendations for consideration regarding its future use and development.
The British Imperial System of Weights used in the United States today derives from a variety of ancient cultures. A Roman contribution is the use of the awkward number 12 as a base. Royal decree established the yard as the distance from the tip of the nose to the end of the thumb of King Henry I. The inch was based on the size of three grains of barley "dry and round." Equally illogically derived units evolved to eventually form the irrational English "system."1
The metric system with its "base-10" or "decimal" system derived its units of mass and volume from its units of length, thus correlating its basic units to each other. The need for further refinement of metrics and a single worldwide and interdisciplinary system of measurements led to the development of the International System of Units (le Systeme International d'Unités) with the international abbreviation "SI." This is sometimes referred to as "the modern metric system" and is said to complete the process of metrication.2
Seventeen countries, including the United States, signed the Metre Convention in 1870. This led to the establishment of the International Bureau of Weights and Measures at Sèvres, France, which acts as an international standards reference laboratory and as the permanent secretariat for the Metre Convention.
- Copyright © 1980 by the American Academy of Pediatrics