BRAND transferpette s Operating Manual page 36

Checking the Volume
Calculation (for nominal volume)
x = Weighing results
i
n = Number of weighings
Mean value x =
A% =
V = Nominal volume
0
Standard Deviation
s = Z ·
*) = Calculation of accuracy (A%) and variation coefficient (CV%):
A% and CV% are calculated according to the formulas for
statistical control.
Note:
Testing instructions (SOPs) and a demo version of the EASYCAL
calibration software are available for download at www.brand.de.
36
Σ x
i
n
Accuracy*
V – V
0 · 100
V
0
Σ (x
– x )
2
i
n – 1
Z = Correction factor
(e.g., 1.0029 µl/mg
at 20 °C, 1013 hPa)
Mean volume V = x · Z
Coefficient of Variation*
100 s
CV% =
V
4.0
TM