Sample Length is the benchmark used to distinguish its
surface roughness.
Evaluation Length is the necessary length for evaluating
the roughness profile. It may include one or more
sampling lengths.
Ra: Arithmetical Mean Deviation of the Profile is
arithmetic mean value of the deviation of the profile within
sampling length.
Rz: The maximum Height of Irregularities is the distance
between maximum depth of the profile peaks and
maximum depth of the profile valley within the sampling
length.
Rq: Root-mean-square Deviation of Profile
Rq is the square root of the arithmetic mean of the
squares of profile deviation (Yi) from mean within
sampling length.
Rt: Total Peak-to-Valley Height
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