
Part Number
Issue
Date
Page
6159937790
12
03/2018
131 / 184
131 (184)
03/2018
9.2
Statistical Computation
9.2.1
CNOMO standard E41.32.110N
Instantaneous standard deviation:
σ
i
Estimated from the mean range
W
of the samples of 5 measurements which form the population.
5
i
d
W
Where:
K
W
W
W = range of measurements on each sample = max. value - min. value
K = number of samples of 5 measurements
K
d
864
.
0
645
.
1
326
.
2
5
, coefficient for a 95% confidence threshold.
Instantaneous dispersion: D
i
i
i
6
D
Process capability: CAM
i
D
IT
CAM
Where:
IT (Tolerance Interval) = Max. tolerance - Min. tolerance
Testing the homogeneity of the population:
Each sample of measurements W must comply with:
CAMcdc
IT
W
643
.
0