Cooling (Only In Centrifuges With Cooling); Standby-Cooling; Pre-Cooling The Rotor; Relative Centrifugal Force (Rcf) - Hettich ROTINA 380 Mode D'emploi

EN
27

Cooling (only in centrifuges with cooling)

The temperature set-point can be adjusted from -20°C to +40°C / -4°F to +104°F. On centrifuges with a
heating/cooling option, the temperature set-point is settable from -20°C to +90°C / -4°F to +194°F. The lowest
obtainable temperature is dependent on the rotor (see Chapter "Anhang/Appendix, Rotoren und Zubehör/Rotors and
accessories").
27.1

Standby-cooling

When the rotor is at a standstill and when the lid is closed, the centrifugal chamber is cooled down to the preselected
temperature if this is lower than 20°C / 68°F.
During the standby cooling, the preset temperature is displayed.
27.2

Pre-cooling the rotor

For rapid pre-cooling of the unloaded rotor and the accessories, it is recommended that the centrifuge is run
with the continuous running settings and a speed of ca. 20% of the maximum rotor speed.
Precooling of the rotor takes place automatically with the PREC (PRECOOLING) program.
•
Press the key. The LED in the
count starts from 00:00.
•
Press the key to end the centrifugation run. Run- down is carried out with the selected run- down
STOP / OPEN
parameters. The run-down parameter is displayed e.g.
Once the rotor has come to a standstill, the LED in the
displayed. The right-hand LED in the
starts blinking and continues blinking until the lid is opened.
During the centrifugation run, the speed of the rotor, or the resulting RCF value, the sample temperature and the
remaining time or expired time are displayed.
28

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.
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key blinks until the rotor has been imported, it is subsequently lit. The time
key also switches off, the left LED in the
STOP / OPEN
2
⎛ ⎞
RPM
⎜ ⎟
= × ×
r 1,118
⎝ ⎠
1000
For more on the centrifugal radius see the chapter " Anhang/Appendix,
Rotoren und Zubehör/Rotors and accessories".
9. The right-hand LED in the
key switches off and OPEN
RCF
⇒ =
RPM
×
r 1,118
key is lit.
STOP / OPEN
OEFFNEN is
key
STOP / OPEN
×
1000