![background image](http://html1.mh-extra.com/html/sigma/134226/134226_operating-manual_1267882062.webp)
2-16KC
Appendix
62
Version 03/2010, Rev. 1.7 of 27/01/2012
Translation of the original operating manual
Quadratic curve no.
Time until 1,000 rpm
Slope as of 1,000 rpm
10
500 sec
4 [rpm / sec]
11
333 sec
6 [rpm / sec]
12
250 sec
8 [rpm / sec]
13
118 sec
17 [rpm / sec]
14
80 sec
25 [rpm / sec]
15
60 sec
33 [rpm / sec]
16
40 sec
50 [rpm / sec]
17
20 sec
100 [rpm / sec]
18
10 sec
200 [rpm / sec]
19
2 sec
1000 [rpm / sec]
Fig. 11.6: Slope of quadratic curves
11.5 Formulae - Mathematical Relations
11.4.1 Relative Centrifugal Force (RCF)
The parameters speed, RCF, and the group rotor and radius cannot
be specified independently. They are interrelated via the following
formula:
RCF = 11.18 x 10-6 x r x n2
If two values are given, the third value is determined by the equation.
If then the speed or the rotation radius is changed, the resulting RCF
will be recalculated. If the RCF is altered, the speed will be adapted
accordingly under the consideration of the radius.
r = radius in cm
n = speed in rpm
RCF without dimension
11.4.2 Density
If the density of the liquid is higher than 1.2 g/cm3, the maximum
permissible speed of the centrifuge is calculated according to the
following formula:
n = n
max
x
)
/
2
.
1
(
Rho
Rho = density in g/cm3
11.4.3 Speed-Gravitational-Field-Diagram
Additional help can be found in the enclosed speed-gravitational-field-
diagram (see fig. 11.7, next page).