Mitutoyo HR-530 Series - Page 269

No. 99MBG518A
G-45
PART G : 4 Results
No. Name Details
⑪
LCL (R graph) Displays the lower control limit on the R graph. The group size
should be seven or more.
LCL = D
3
R
This is displayed as a red dotted line in the R graph.
⑫
[X-R graph] button Indicates that this screen displays the X-R graph.
⑬
Save button Savesahardcopyofthescreen(BMPle)totheUSBmemory.
⑭
Exit button Closes the X-R graph.
Tips
• X = Total of the averages of the groups/number of groups (average hardness value for each specimen)
• R = Total of the ranges of the groups/number of groups (average dispersion value for each specimen)
Coe󰀩cientforcalculatingthecontrollimit(source:JISZ-9020-2:2016)
Size of group A2 D3 D4
2 1.880 — 3.267
3 1.023 — 2.575
4 0.729 — 2.282
5 0.577 — 2.114
6 0.483 — 2.004
7 0.419 0.076 1.924
8 0.373 0.136 1.864
9 0.337 0.184 1.816
10 0.308 0.223 1.777
Tips
When a group size is out of the range, the control line (value) of the group is not displayed.
Example:
A
2
= 1.023
D
3
= None
D
4
= 2.575
X = (total of the averages of the groups) / 6
R = (total of the ranges of the groups) / 6
Group size = 3
(The number of measuring
points for each specimen)
Number of groups = 6
(The number of specimens
measured)