Probability density function (ADF)

Surface Roughness Parameters

ADF displays the probability of height Z(x) obtained across the evaluation length. The derivative of the BAC data is also determined. These derivatives use the three-point formula shown on the right.

When n=0 or N, calculations are carried out with BAC (-1) = 0.0 and BAC (N+1) = 100.0. Because the vertical range is the same as BAC, this is shown on the same graph. However, the graph is automatically adjusted so that the maximum value on the horizontal is 80%.

Surface Roughness Parameters

This section explains the main parameters of ISO 4287:1997. Each parameter is classified according to primary profile (P), roughness profile (R), and waviness profile (W) in order to evaluate different aspects of the profile. (When the wavelengths of the waviness and primary profile components are compared, the surface roughness component is the asperity component of that which has the comparatively shorter wavelength.)

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Peaks and valleys in the height direction	Arithmetical mean height (Ra, Pa, Wa)
	Maximum height of profile (Rz, Pz, Wz)
	Maximum profile peak height (Rp, Pp, Wp)
	Maximum profile valley depth (Rv, Pv, Wv)
	Mean height of profile elements (Rc, Pc, Wc)
	Total height of profile (Rt, Pt, Wt)
Average amplitude in the height direction	Root mean square deviation (Rq, Pq, Wq)
Average characteristics in the height direction	Skewness (Rsk, Psk, Wsk)
Average characteristics in the height direction	Kurtosis (Rku, Pku, Wku)
Horizontal direction	Mean width of the profile elements (RSm, PSm, WSm)
Hybrid	Root mean square slope (R∆q, P∆q, W∆q)
Areal material ratio curve and probability density function	Load length ratio (Rmr (c), Pmr (c), Wmr (c))
	Profile cut level difference (Rδc, Pδc, Wδc)
	Relative load length ratio (Rmr, Pmr, Wmr)
	Material ratio curve (BAC)
	Probability density function (ADF)

"What is line roughness?" page list

Surface Roughness Parameters

Surface roughness parameters in JIS B 0601