Relative Centrifugal Force (Rcf); Centrifugation Of Materials Or Mixtures Of Materials With A Density Higher Than 1.2 Kg/Dm; Emergency Release - Hettich MIKRO 200 Serie Bedienungsanleitung

EN
21

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:
RCF
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
The relative centrifugal force (RCF) stands in relation to the revolutions per minute and the centrifugal
radius.
22

Centrifugation of materials or mixtures of materials with a density higher than 1.2 kg/dm

When centrifuging with maxim revolutions per minute the density of the materials or the material mixtures may not
3
exceed 1.2 kg/dm .
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:
Reduced speed (n )
red
e.g.: maximum speed RPM 4000, density 1.6 kg/dm
1.2 kg/dm³
n = x 4000
red
1.6 kg/dm³
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:
Reduced speed (n )
red
e.g.: maximum speed RPM 4000, maximum load 300 g, actual load 350 g
300 g
n = x 4000 RPM
red
350 g
If in doubt you should obtain clarification from the manufacturer.
23

Emergency release

During a power failure the lid cannot be unlocked by motor. An emergency release has to be executed by hand.
For emergency release disconnect the centrifuge from the mains.
Open the lid only during rotor standstill.
See figure on page 2.

Switch off the mains switch (switch position "0").

Look through the window in the lid to be sure that the rotor has come to a standstill.

Insert the hexagonal wrench key into the bore hole (Fig. 1, A) and carefully rotate by half a turn in clockwise
direction until the lid can be opened.

Pull the hexagon socket head wrench out of the drilling again.

If the left LED in the
OPEN / STOP
button so that the motor-driven lid lock goes into the basic position (opened) again.
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2
 
RPM
 
  
r 1,118
 
1000
container. For more on the centrifugal radius see the chapter
"Anhang/Appendix,Rotoren und Zubehör/Rotors and accessories".
1.2
=
Greater density [kg/dm³]
3
RPM = 3464 RPM
maximum load [g]
= x maximum
actual load [g]
= 3703 RPM
button flashes after the centrifuge is switched on again, press the
Rev. 09 / 04.2020
RCF
 
RPM

r 1,118
x maximum speed [RPM]
speed [RPM]

1000
3
OPEN / STOP
AB2400DEENFRIT