Carter, By the rowlett definition, Hz is restricted to a "periodic" cycle (with a (at least implied) fixed frequency of rotation.
In many cases of rotating shafts, the rate of rotation is a variable, not periodic. In these cases, the rowlett definition must be rejected. In contrast, the BIPM Brochure does not require cycles measured by the Hz to be constant. Thus, the Hz is acceptable for a variable rate of shaft rotation, but I would prefer rev/s for simple cases of rotating shafts, or rad/s for more complicated cases of rotations where the calculus and differential equations are the appropriate tools. For example, analysis of a rigid body "tumbling" about all three axes. Gene. ......................................... On Wed, 17 Jul 2002, Carter, Baron wrote: > If we accept the following definition of Hz (from > http://www.unc.edu/~rowlett/units/dictH.html) then surely Hz would be the > obvious choice in replacing rpm? > > "the SI unit of frequency, equal to one cycle per second. The hertz is used > to measure the rates of events that happen periodically in a fixed and > definite cycle; .............."
