Reference Base of the Volt To Be Changed

Abstract Next Jan. 1, 1969, the National Bureau of Standards (NBS) expects to change the value of the U. S. legal volt by 1 part in 100,000. The change represents a better measurement of the value of the U. S. volt, as maintained by a group of standard cells, in terms of the "absolute" volt, which is derived from the basic mechanical units of length, mass, and time.