The International System of Units (SI), Physical Quantities, and Their Dimensions
international system of units In this chapter, we introduce the International System of Units (SI) on the basis of the SI brochure “Le Système international d'unités (SI)” [2.1 ], supplemented by [2.2 ]. We give a short review of how the SI was worked out
- PDF / 420,308 Bytes
- 15 Pages / 547.146 x 686 pts Page_size
- 59 Downloads / 202 Views
The Internatio 1.2.1
The International System of Units (SI) ...
11
1.2.2 Physical Quantities .............................
12
1.2.3 The SI Base Units ................................ 1.2.3.1 Unit of Length: the Meter ......... 1.2.3.2 Unit of Mass: the Kilogram ....... 1.2.3.3 Unit of Time: the Second .......... 1.2.3.4 Unit of Electric Current: the Ampere ............................ 1.2.3.5 Unit of (Thermodynamic) Temperature: the Kelvin .......... 1.2.3.6 Unit of Amount of Substance: the Mole ................................ 1.2.3.7 Unit of Luminous Intensity: the Candela ............................
13 13 14 14 14 14 14 15
1.2.4 The SI Derived Units ............................
16
1.2.5 Decimal Multiples and Submultiples of SI Units................
19
1.2.6 Units Outside the SI ............................ 1.2.6.1 Units Used with the SI.............. 1.2.6.2 Other Non-SI Units ..................
20 20 20
1.2.7 Some Energy Equivalents.....................
24
References ..................................................
25
1.2.1 The International System of Units (SI) All data in this handbook are given in the International System of Units (Système International d’Unités), abbreviated internationally to SI, which is the modern metric system of measurement and is acknowledged worldwide. The system of SI units was introduced by the General Conference of Weights and Measures (Conférence Générale des Poids et Mesures), abbreviated internationally to CGPM, in 1960. The system not only is used in science, but also is dominant in technology, industrial production, and international commerce and trade. Who takes care of this system of SI units? The Bureau International des Poids et Mesures (BIPM), which has its headquarters in Sèvres near Paris, has taken on a commitment to ensure worldwide unifi-
cation of physical measurements. Its function is thus to:
• • • •
establish fundamental standards and scales for the measurement of the principal physical quantities and maintain the international prototypes; carry out comparison of national and international standards; ensure the coordination of the corresponding measuring techniques; carry out and coordinate measurements of the fundamental physical constants relevant to those activities.
The BIPM operates under the exclusive supervision of the Comité International des Poids et Mesures (CIPM), which itself comes under the authority of the
Part 1 2
In this chapter, we introduce the International System of Units (SI) on the basis of the SI brochure “Le Système international d’unités (SI)” [2.1], supplemented by [2.2]. We give a short review of how the SI was worked out and who is responsible for the further development of the system. Following the above-mentioned publications, we explain the concepts of base physical quantities and derived physical quantities on which the SI is founded, and present a detailed description of the SI base units and of a large selection of SI derived units. We also discuss a number of non-SI units which still are in use, especi
Data Loading...
