Berechnung von Richtigkeit (R%)
und Variationskoeffi zient (VK%):
Richtigkeit (R%) und Variationskoeffi zient (VK%)
werden nach den Formeln der statistischen Qualitäts-
kontrolle berechnet.
Calculation of accuracy (A%)
and coeffi cient of variation (CV%):
Accuracy (A%) and coeffi cient (CV%) are calculated
according to the equations used in statistical quality
control.
- 15 -
Berechnung
(für Nennvolumen)
Mittelwert x
_
=
∑
x
i
x
i
= Wäge-Ergebnisse
n
n = Anzahl der Wägungen
Mittleres Volumen V
_
= x
_
· Z
Z = Korrekturfaktor
(z. B. 1,0029 µl/mg bei 20 °C, 1013 hPa)
Richtigkeit
R%
=
V
_
- V
0
· 100
V
0
= Nennvolumen
V
0
Standardabweichung Variationskoeffi zient
s = Z ·
√
∑
(x
1
- x
_
)
2
VK%
=
100 s
n - 1
V
_
Calculations
(for the nominal volume)
Mean value x
_
=
∑
x
i
x
i
= results of weighings
n
n = number of weighings
Mean volume V
_
= x
_
· Z
Z = correction factor
(e. g., 1.0029 µl/mg at 20 °C, 1013 hPa)
Accuracy
A%
=
V
_
- V
0
· 100
V
0
= nominal volume
V
0
Standard deviation
Coeffi cient of variation
s = Z ·
√
∑
(x
1
- x
_
)
2
CV%
=
100 s
n - 1
V
_
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