Basic and supplementary units

A meter(ni) is 1 550 763.7 wavelengths in vacuo of the radiation corresponding to the transition between the energy levels and 5dg of the krypton 86 atom. 

A second (sec) is the interval occupied by 9 192 631 770 cycles of the radiation corresponding to the transition of the caesium-133 atom when unperturbed by exterior fields. 

An ampere is the constant current which if maintained in two parallel recti-linear conductors of infinite length of negligible circular cross-section and placed at a distance of one meter apart in vacuo would produce between these conductors a force equal to 2 x 10 newton per meter length. 

A candle is such that the luminance of a full radiator at the temperature of solidification of platinum is 60 units of luminous intensity per square centimeter. 

A mole (mol) is the amount of substance which contains as many 

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Constants and Conversion Factors Basic and Supplementary Units Derived Units and Quantities Physical Constants Properties oe Water Periodic Table of the Elements... 

With the current trend toward metrication, the question of using a consistent system of units has been a problem. Wherever possible, the authors of this Handbook of Environmental Engineering series have used the British system (fps) along with the metric equivalent (mks, cgs, or SIU) or vice versa. For the convenience of the readers around the world, this book provides a 55-page detailed Conversion Factors for Environmental Engineers. In addition, the basic and supplementary units, the derived units and quantities, important physical constants, the properties of water, and the Periodic Table of the Elements, are also presented in this document. 

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