3D S Parameters - Hybrid Parameters
Sdq (Root Mean Square (RMS) Surface Slope)
Sdq is the Root Mean Square (RMS) Surface Slope comprising the surface, evaluated over all directions.
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Sa = 80 nm, Sdq=11.0 deg |
Sa = 75 nm, Sdq=0.2 deg |
Application
Sdq is a general measurement
of the slopes which comprise the surface and may be used to differentiate
surfaces with similar
average roughness, Sa. Sdq may find application
for sealing systems, surface cosmetic appearance and may be related to the degree
of surface wetting by various fluids. Sdq is affected both by
texture amplitude and spacing. Thus for a given Sa, a wider
spaced texture may indicate a lower Sdq value than a surface
with the same Sa but finer spaced features, as demonstrated
above.