FISCHER MMS - Page 97

Glossary
93
MMS
®
Inspection DPM High
13.2.2 Display texts – Description of statistical characteristics
Coefficient of Variation (V[%])
Coefficient of variation (V [%]). Percent variation of a series of measurements,
i.e. standard deviation relative to the arithmetical mean value. The coefficient of
variation is a characteristic process constant. A sudden change in the coeffi-
cient of variation indicates a change in process conditions.
Mean value ( )
Arithmetic mean value (x
) of all measured readings per individual climatic val-
ues. The arithmetic mean value is the summation of all measured readings x
i
of a batch, divided by the number of measured readings (n).
Number (n)
Number of all measured readings in a batch per individual climatic value
Range (R)
The range equals the difference between the largest and the smallest mea-
sured reading in a batch.
Standard Deviation (s)
Standard deviation is a degree for the variation of individual measured readings
(of a batch) around their common mean value. It equals the mean square devi-
ation of the measured readings from the mean value.
Legend
V: Coefficient of variation
s: Standard deviation of a batch
x
:Mean value of a batch
V
s
x
--
100 %[]⋅=
x
Legend
x
: Mean value
n: Number of measured readings
x
i
: Measured readings
x
1
n
---
x
i
i 1=
n

⋅=
Legend
R: Range
x
max
:Highest measured reading
x
min
:Lowest measured reading
Rx
max
x
min
–=