I am looking for the definition of "ips" (in/sec) as used to describe
the state of a propeller balance/imbalance.  This definition may also
apply to rotating machinery in general.  I used plots of acceleration of
my engine/prop to achieve a better dynamic balance.  The plots were
produced using an accelerometer and scope .  I would like to convert my
results to industry standard units for the sake of comparison with
typically obtained values using commercial balancers.  
Some guesses for the definition are:  RMS value of velocity or peak
velocity???
Chris Zavatson
N91CZ std 360