At 11:15 PM 3/30/2009, Scott Daniel - Turbovans wrote:
>surface condition ............I want to say 'RMS' number......
>something like that - but the surface of your new disc is suppossed to be of
>the correct roughness as it comes out of the box,

The Root of the Mean of the Squares of the variations in surface
height, typically in microns...gives a particular type of effective
"average" for surface roughness -- in fact the same one that gets you
the effective value of an electric power waveform that's not a true
sinewave.  If it *is* a true sinewave, the RMS value of voltage
equals the square root of 2 times the peak value, which is easy to
calculate/measure.  So if your AC voltmeter doesn't claim to measure
"True RMS" it will only be accurate on pure sine waves.

  --
David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
'89 Po' White Star "Scamp"