Hettich 1008-00, Руководство по эксплуатации

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© 2017 by Hettich AG page 30 CW II-OM-rev1.1
Hettich AG
Laborapparate phone: +41 44 786 80 20
Seestrasse 204a e-mail: info@hettich.ch
CH-8806 Baech internet: www.hettich.ch
10.4 Relative centrifugal force (RCF)
The relative centrifugal force (RCF) is given as a multiple of the acceleration of gravity (g). It is a unit-free value and
serves to compare the separation and sedimentation performance.
These values are calculated using the formula below:
1,118 r
2
1000
RPM
RCF
  =







1000
1,118 r
RCF
RPM


=
RCF = relative centrifugal force
RPM = rotational speed (revolutions per minute)
r = centrifugal radius in mm = distance from the centre of the turning axis to the bottom of the centrifuge.
For more on the centrifugal radius see the chapter ” Anhang/Appendix,
Rotoren und Zubehör/Rotors and accessories”.
The relative centrifugal force (RCF) stands in relation to the revolutions per minute and the centrifugal
radius.
10.5 Querying operating hours
Go into the system settings (start screen, cha. 8.2, pos. 2),
Go into the service menu (system settings, cha. 8.5, pos. 2),
11 Centrifugation of materials or mixtures of materials with a density higher than 1.2 kg/dm
3
When centrifuging with maxim revolutions per minute the density of the materials or the material mixtures may not
exceed 1.2 kg/dm
3
.
The speed must be reduced for materials or mixtures of materials with a higher density.
The permissible speed can be calculated using the following formula:
[RPM] speed maximum x
[kg/dm³] density Greater
1.2
= ) (n speed Reduced
red
e.g.: maximum speed RPM 3500, density 1.6 kg/dm
3
RPM 3031 = RPM 3500 x
kg/dm³ 1.6
kg/dm³ 1.2
= n
red
In the exceptional case that the maximum loading indicated on the hanger is exceeded, the speed must also be
reduced.
The permissible speed can be calculated using the following formula:
[RPM] speed maximum x
[g] load actual
[g] load maximum
= ) (n speed Reduced
red
e.g.: maximum speed RPM 3500, maximum load 300 g, actual load 350 g
RPM 3240 = RPM 3500 x = n
g 350
g 300
red
If in doubt you should obtain clarification from the manufacturer.