GENERATION, CONTROL, AND MEASUREMENT 135 



second (cgs) and the meter-kilogram-second (mks). The mks system is 

 replacing the cgs system of units in physics and engineering because the 

 mks units are more suitable for practical use. An excellent discussion 

 of the various systems is given by Crittenden (1944, 1950). 



Table 3-6. Conversion Factors of Radiant Energy, Power, and Intensity Units 



The basic unit of energy in the cgs system is the erg, defined as the 

 work done when a force of 1 dyne is applied through a distance of 1 cm. 

 The dyne is the force required to give a 1-g mass an acceleration of 

 1 cm/sec^ The energy unit of the mks system is the joule, which is 



