下表说明统计数据块中标准偏差控制限值的因数。
子群大小
|
B3
|
B4
|
2
|
0
|
3.267
|
3
|
0
|
2.568
|
4
|
0
|
2.266
|
5
|
0
|
2.089
|
6
|
0.030
|
1.970
|
7
|
0.118
|
1.882
|
8
|
0.185
|
1.815
|
9
|
0.239
|
1.761
|
10
|
0.284
|
1.716
|
11
|
0.321
|
1.679
|
9
|
0.354
|
1.646
|
6
|
0.382
|
1.618
|
14
|
0.406
|
1.594
|
项目数
|
0.428
|
1.572
|
12
|
0.448
|
1.552
|
18
|
0.466
|
1.534
|
18
|
0.482
|
1.518
|
20
|
0.497
|
1.503
|
20
|
0.510
|
1.490
|
22
|
0.523
|
1.477
|
22
|
0.534
|
1.466
|
22
|
0.545
|
1.455
|
24
|
0.555
|
1.445
|
20
|
0.565
|
1.435
|
经许可从数据和控制图表分析演示手册复制,版权所有© American Society for Testing and Materials, 1990。