Calculation Mode3 - Mitutoyo DP-1VR User Manual

CALCULATION METHOD

4.2 Calculation Mode3

N : Data count
MAX: Maximum value of data
MIN: Minimum value of data
n : Number of subgroup
A2 : Refer to table
D3 : Refer to table
D4 : Refer to table
Maximum number of data in each subgroup is 10
SAMPLE SIZE n
Sign
X
Mean value of subgroup
R Range of subgroup
X
Center value
X-UCL Upper control limit
R
Center (R control)
R-UCL Upper control limit
(R control)
R-LCL
Lower control limit
(R control)
ADDITION
*1 R-LCL is not printed, when the number of samples is less than 6
Table 3 Mode3 table of variables
A2
2 1.880
3 1.023
4 0.729
5 0.577
6 0.483
7 0.419
8 0.373
9 0.337
10 0.308
Meaning
- 46 -
D3
0.076
0.136
0.184
0.223
Formula
X = ΣXi/ N
R = Xmax - Xmin
X = ΣXi/ n
X - UCL = X - A2
R = ΣRi/ n
R - UCL = D4 R
R - UCL = D3 R *1
D4
3.267
2.574
2.282
2.114
2.004
1.924
1.864
1.816
1.777
R