Mitutoyo SURFTEST SJ-410 - A2 (JIS2001, ISO1997, VDA, Free): Valley Area

23. REFERENCE INFORMATION
No. 99MBB765A
23-35
23.5.35 A2 (JIS2001, ISO1997, VDA, Free): Valley area
From the lines that are obtained by selecting 2 points (point A and point B) on the BAC
(material-ratio profile) that differ in mr value by 40%, obtain the line with the smallest
inclination. Set point C and point D to be the points where the obtained line intersects the
lines at mr = 0 and mr = 100. Set point E to the point on the BAC with the same slice level
as point D, and then set point F to the point were the BAC and the slice level at mr = 100
intersect. Next, set point G along mr = 100, so that the area enclosed by line segment DE,
line segment DF, and curve EF and the area of triangle DEG are the same. A2 is the area
of triangle DEG. (Valley area)
Valley area A2
D
G
H
C
A
B
E
A2
A1
Rk
Rvk
Mr1
Mr2
40%
J
F
Rpk
I
Rvk
DEPTH (µm)
mr[c] (%)